THE NATURALIST.

Otago Witness, Issue 2666, 19 April 1905, Page 72

THE NATURALIST.

Alliances Between Plants and Animals.

Very noteworthy are some of the methods adopted in resisting' animal invaders ; cooperation, it is scarcely necessary to add, being a principle not unrepresented in plant existence.

There is a narasitio plant of Sumatra, in the East Indies, for instance, which has established singular relations with ants. TLese insects inhabit the tuber of the plant, which itself is a parasite on trees. Within this tuber the ants burrow to form their nests and winding passage* ; and, inasmuch as these insects sting very severely, it become® clear that animals will be chary of meddling with their plant host. A partnership of a similar kind is seen in a well-known member of the Acacia genus, provided with spines of large size born© on the stem, and branches. Below, ea<?h of these thorns is hollow-eel out, and in the receptacle thais formed ants are found. There is not merely a leaning upon the insect for defence in such a case, but also a deoid«d preparation for the comfort and habitation of the defenders in the shape of the hollow spines, and, further, in the form of a largj gland which manufactures the nectai on which the ants subsist. In return for defence, the plant offers board and lodging to the insects, and provides a hospitable breakfast table for their use. By this means the acacia secures a strong army to protect its leaves from all kinds of herbivorous mammals and insects.

Since the days when a work on flowers and their unbidden guests was penned, botanists have furnished charming stories of the quaint and often marvellous ways in v.hich plants, while inviting certain insects to treir stem and leaves, meanwHile defend themselves against invasion by other and undesirable insect foes.

Ants on Horseback. — A French traveller has discovered a new species of ant in Siam, or at least a new trait he has never before seen recorded. The creatures were small, of a grey colour, and lived in damp places. They travelled often and in troops which seemed to be under the direction of a commander who rode- on "horseback." M. Meissen, the Frenchman who noticed this peculiarity, was attracted to these groups by discovering that each company contained a large ant that travelled more rapidly than the others. Observing them, more closely, he noted that each large ant always carried a small grey ant upon its back, though tie remainder of the troop were on foot. This mounted ant would ride out from the line, travel swiftly along the column from head to refer, and apparently overlook their manoeuvres. M. Meissen concluded from what he saw that this species of ant, while on its travels, is under the direction of a commander, though such " ant-horses " as the general rides must be rare and valuable; for he ecarcely ever found more than one mounted ant in a colony.

An Insect-catching Grass. — One of the most curious, and at present most inexplicable, adaptations of a natural remedy to a. pest is to be found in the insectcatching graes of Cuba. This grass has been recently described by Mr E. A. Schwarz. With the beginning of the rains in Cuba countless swarms of insects appear. At this time also a grass becomes common which, catches multitudes of 111sects in its flowering spikes. They are caught day and' night, and in incredible number. The spiny covering of the spikelets of the grass presents a bristling array to all-comers. Wings of insects alighting or flying within reach are pierced and entangled by the minutely barbed spines and become inextricably matted. Sometimes an insect is caught by the leg. It is not only the weak insects that are caught. Numbers were caught of the Cuban luminous snapping beetle, which is so large and strong that it can be held in the hand with difficulty, and then only by naturalists who have presence of mind. Two insects, however, differ from the rest of the captives, and are able to free themselves. One of them is an earwig; another resembles the ladybird. There seems to be no possible advantage to the grass in its capture of insects. It is itself a pest, and grows in the rich soils along the edges of sugarcane fields. It *s found in the West Indies.

Big Game of North America. — In the interesting book on the big game of North America which has been recently published, Mr Dwight Huntington remarks that the extraordinary activity of the American bison, added to its speed and staying power, contributed to the difficulty of shooting it. Tli© bison ooulcl " run down the steepest and most precipitous places at full speed, going 1 over the edges of high hills, ajid racing or sliding down their steep sides, where no horseman would dare to follow at a walk, and climbing up similar places with an agility equal to that of a goat." On one occasion, when Mr Huntington was in full chase of a small herd, the bison headed for an almost perpendicular cliff, a hundred feet or more in height, which overhung a little river valley. " The face of the cliff was loose earth ; only a few shrubs of the wild sage clung to its sides. Over this cliff the bison plunged headlong, and went racing or sliding down to the valley below. . . I drew rein at the brink, and, seeking an easier place, attempted the descent on foot, driving my horse on ahead, since there was great danger of his falling. Sliding slowly down, grasping at every bush, I at length reached the bottom, but the buffaloes were miles away, going at top speed. It was useless to follow them."

Royal Zoologists. — Two European rulers — the King of Portugal and the Prince cf Monaco — are enthusiastic students of marine zoology. Both maintain steam yachts admirably fitted up for collecting specimens of large and small fauna, and investigating matters connected with fisheries, ocean currents, salinitz, the food of fish, and the like. When the King of Portugal recently visited King Edward ho presented to the Natural History Museum a collection of fishes that had been taken during some of his cruises. Most of them vere sharks, dogfish, or rays, for the capture of which fisheries have been carried on for many years on the JPortuguese coast. One cf the most important specimens is the frilled shark, originally described from Japan, but since obtained in the Atlantic. This primitive form owes its name to the fact that the gills are covered with flaps of skirf. Part of the collection is now on view in one of the bays of the Central Hall. Fish specimens in spirit ar-e not very attractive; but everybody will appreciate the strange-looking, hammer-hesjl&3k shark.

which has been mounted. The frontal port;on of the head is expanded into a lobe on each side, and on the*e the eyes are situated. In an adjacent ca-:e arc exhibited the King's reports on the tunny fisheries the sharks of the Portuguese, waters, the cruises of his yacht Amelia, ami the first part of an illustrated catalogue of the bird-, of Portugal, perhaps to show that tho. King's interest in sociological matters is by no means confined to fishes.