AUCKLAND INSTITUTE.

New Zealand Herald, Volume XXXVII, Issue 11432, 24 July 1900, Page 3

AUCKLAND INSTITUTE.

" THE SEXUAL WORY IN PUNTS " Last evening Mr. D. Petrie, F.LB dehvorod a popular lecture before the member* of the Auckland Institute on "The Sexual Theory m Plants." There was a good attendance. Professor Sogar (president of the institute) briefly introduced the lecturer. Mr 1 etrie read an exhaustive paper on the tonic winch he had selected, and lucidly explained .1 series of diagrams on the'walls, which ef fecUyoly illustrated hi, subject. Mr. Petrie said (hat though the question of the sexuality of plants was much discussed in ancient time's a! during the latter Part of the Middle Ages, it wag not till the close of the 17th century that any real light was thrown on ho subject. Before that time the doctrine had no sound or scientific foundation, but was based on assumed analogies between plants and animals, and other uncertain data I no first question to be settled in establishing the sexual theory in plants was whether or nor seed, capable of germination, could be formed m the oviary without the co-operation •of the pollen. This was a question that coul. lie decided only by one method, namely, by the experimental interrogation of nature. He then reviewed the researches and discoveries of Camorarius, Koolrouter, Sprengel, and Gnertner, as to the sexuality of plants. Koelreuler's chief work was the production and varied study of hybrid or mongrel plants. His experimental investigations in this domain were so skilfully directed that none of his results have been changed by later investigations, while in combination with the latter (hey have been used for the discovery of goneral laws in hybridisation. Coming to later times, Mr. Petrie said after 1850 the sexuality of plants was admitted by all competent judges, and it had never been called in question since. With all his gonitis and laborious activity Oaortner did not understand or duly appreciate Sprengel's grand conclusions about the relation of the structure of tbo flowers to the insect world, and he thus missed the most fruitful source of new and fertile developments. It was reserved for Darwin's wonderful talent for combination to Bum up the results of Uho investigations of a hundred years, so that now all the physiological arrangements of the flowers have becomo an intolligiblo book in their relations to fertilisation, and in their dependence on the natural conditions under which pollen action takes place in nature, without the interference of man. The investigation of the minute processes oonnectcd with the fertilisation of flowering plants was a matter of great difficulty, and demanded tho highest skill in microscopic manipulation. It look nearly 200 years for tho world of science to accept Camerarms' doctrine that plants had sex just in tho same sense as the higher animals possess sex. It had taken Jess than 50 years to traco out the details of the process, and thus to establish the dootrine of the sexuality of plants on a basis of observation that could be verified by any trained and painstaking investigator. In concluding, the lecturer said that ho had chosen to given them an historical survey of the question of the sexuality of plants from tho conviction that in most branches of science this mode of treatment was the most instructive as well as the most intelligible and interesting. The survey showed how slow and _ halting tho development of scientific inquiry must be while only a few men took an activo interest in its study. In the fulness of time tho field would become full of workers, criterion of validity in experimental results would bo established and recognised, and progress, stimulated by the cooperation, and not less by tho criticism of many independent inquirers, would become sure and rapid. Botanists had now reached ' that stago which could not bo far from a final knowledge of the visible mechanism of plant fertilisation. The reading of tho deop significance of tho process was a matter of speculation, as to which no certain or farreaching conclusions had at present bocu secured. Whether certain results in its interpretation were within our powers, the future alone could decide. On the motion of the chairman, seconded by Dr. A. G. Purchas, who spoke in complimentary terms, a hearty voto of thanks was accorded by acclamation to Mr. Petrie for his able and instructive paper. I