COLOUR AND DISEASE.

Otago Witness, Issue 2362, 1 June 1899, Page 54

COLOUR AND DISEASE.

The following paper, by Mr Richard Henry, Resolution Island (which Mr Henry has revised and enlarged), is from an advance copy of the Transactions of the New Zealand Institute: —

In 1881, at Manapouri station, there were a good many wild cats out on the run, and reddish ones were common ; but I heard that these were always males, which accorded with my own limited experience. I found several nests of tabby kittens during my two years up there, but most of them were half blind and sickly, and I found several half-grown young cats that had apparently died of distemper, so that I thought the disease might prevent them being of great use against the rabbits.

However, the red ones always looked big and healthy, bub it took me ten years to realise that there might be some relationship between that colour and the liability to distemper, which was very hard on dogs up there at that time. I tried to rear some pups then, but they all died except some reddish ones that never took sick at all, and grew into fine dogs. But I did not take the hint until 1891, when at Te An&u Dp_wns Btation there was a half-wild

cat with a litter of kittens not far from thehouse, and as they grew up I noticed that there was one red one, and that some of the others were sick. I took no more notice of them till one day the red one happened right in my path, and as it was too weak to run away, I took it up and found that it was very light, just skin and bone, but healthy-looking in the eyes, so I took it to the house and fed it, and it soon got all right and playful. Then I formed a theory — that if such a starved thing as that was had taken the disease, it could not have survived, and that possibly red cats were proof against distemper. This one was reared in a nest where I knew there was sickness, and I think all the rest of the family died, so that it must have had a different constitution, and the colour may have been the outward sign of it. I had read in " Origin of the Species " that there was some sickness in Virginia thai killed white pigs, while black ones were exempt ; and we know that something of the same kind happens with the men in fever countries. I also remembered a young dingo in Victoria that never took sick, though tied up in an infected kennel where other pups had died, and you know that dingos are /ill the same colour as those red cats, excepting the slightest brindle markings. Perhaps it is immunity from this fatal disease that controls the 'colour of the dingoes — or in other words, that the colour and immunity may be co-relative"; "and that their immunit.y from the most fatal disease is the cause of uniformity of colour in wild animals. Foi instance, in Africa zebras are proof against tsetse, a poisonius fly that kills horses, which indicates as great a difference in constitution as in colour.

Thus we get a hint that colour may not be only for " protection," as naturalists hold, or for beauty, but may be the outward sign of a special constitution. And the idea is very becoming to Nature's beautiful plans in everything. This is new to me in a wide sense, and I am confident that if taken up and followed out it might be of great practical value in dealing with many difficult questions — possibly even tuberculosis in cattle.

It might solve the rabbit question in Australia, because cats living "wholly on rabbits are specially liable to the fatal distemper, and if it were not for that, I- think they would be a match for them in the back country, because they catch them with the smallest expenditure of energy by lying in wait, and are otherwise the most harmless animals of their class. The tortoiseshells, which are always females, might be the mates' for the red males. There is a well-known, relationship between colour and disease in the many white cats that are deaf.

In the Otago Witness of November 17, 1898, page 6, there is an article on the wild white cattle of Europe, which is very suggestive from this point of view, f6r it shows their great antiquity and wide distribution, and even in one sentence says : — "Why a wild race of cattle could not be of ■white colour no explanation is given "—because Professor Boyde-Dawkins had said that their white colour was fatal to the idea of them being of a pure wild breed. Evidently lie thought that colour was only " protective," and in no way indicative of constitution. A majority of the white cattle may have been proof against some of those fatal diseases that^seem to be gaining ground of late years, and that would account for their long existence and wide distribution in the face of their conspicuous colour.

This suggests that during epidemics the colour of those not taking sick should be carefully noted and fostered, instead of adopting some fancy colour, as often happens, without rhyme or reason. The piebald horse might be the germ of the zebra's constitution to be improved by cultivation and experiment.

In the cases of dogs and cats where only part of the litters are reared, those that varied in the proof direction would survive if left to themselves, _and this would soon cause uniformity of colour in wild animals, such as dingoes and wolves, which are independent of colour for protection. Men's whimsical tastes may be the cause of our many-coloured tame animals ' and their greater liability to disease. We test horses by rearing and working them, and breed fiom the best, which results in a fairly uniform colour ; but we have no constitutional test for cows, and therefore they are patched with i all colours. This is the system that leaves our cattle open to fatal difeea&es &uch as pleuro-Tineumonia, and rinderpest, running riot every now and then, and leaving us proof constitutions for a fresh start, if we only knew how to recognise them and value them. I remember when the pleuro-pneumonia went through Victoria and took about 70 per cent, of the cattle, ruining many farmers who previously regarded themselves as independent.

If colour were found to indicate constitution even in a small way, the best individuals could often be saved in picking out those for beef, so that it might become of very great value to farmers if always kept in view. The colours of the American buffalo, the zebra, and a ho&t of wild cattle and antelopes are certainly not solely for protection ; but their uniformity in each case is suggestive that it was the colour that went with a constitution proof against their own epidemics ; and the same might be paid of the men in well-defined countries. For instance, the introduction ot rinderpest to the South African cattle may seriously injure a fine race as the measles injured the Fijians, and some of our own ailments injure the Maoris. Therefore, there should be no more quarantine, but rather prohibition. Proof constitution seems a clumsy term ; but I saw it was used the other day in picking out soldiers to stand the yellow fever in Cuba, though I do not know if there was any shade of colour selected as a guide. Like other useful laws, it may be too long in abeyance through the interference of " civilisation. "

The buffaloes had no need to hide from' any enemy but man, and it could not have been success in that direction that controlled the colour. Therefore, we must look for some other cause for its uniformity in opposition to the ever-pressing law of variation. Of course it is not claimed that

colour, has any effect on constitution, or vice versa ; but that they may be co-related in the same way as the pink eyes and white colour of .the albinoes and the deafness of white cats. Then, as we have no means of knowing the subtle differences of constitution, an obvious co-relative would be highly valuable in directing us what to save and foster.

A uniformity of colour says plainly that there is some ever-present cause for it, and I think that in a very large number of. cases it could have been in no way protective, for how could it be so from enemies that hunt by scent and at night, which are generally the worst of all? It is far easier to understand that a long persistent colour is purely the co-relative of the best constitution in cases where disease is the worst enemy. We knoAv that a strong constitution often resists disease; and that this is essentially a fighting world, for even the trees compete; that the fight is the most important ordeal among animals, evidently designed to test constitution and allow the best to succeed : and in that ordeal, colour, either for beauty or protection, played no part.

After the fight I can think of no other satisfactory physical test but racing and man's control ; for I think he has modified many animals, especially the horse, and probably the camel. He took a thick-tailed clumsy creature long ago, and by saving the best for his purpose for ages, and by mutual benefit, developed the beautiful horse. Dar-i win, on seeing a naked man on horseback, noted how exactly they suited each other, and hinted that man had trained up the form of the horse as he might train a rose bush; which implies that he may be training up bad constitutions by not testing them according to natural law. No one ever heard of a farmer setting two bulls to fight to see which was the better in heart and lungs and muscle — yet that is Nature's plan, and it must be right. Our method of judging prize animals by points leaves out of consideration the internal organs, which are most important; yet* Aye arrive at fair conclusions, unconsciously, by using the^co-relatlonship between" outward appearances and internal organisation. The object of this paper is to point out that there may be other co-relationships and a conscious way of using them.