October 1, 1898.] 



KNOWLEDGE 



227 



who had been nominated President, but had found himself 

 unable to accept the post owing to continued ill-health. 



In the afternoon, in Section A (General Zoology), among 

 others Prof/ Mitsukuri, of Tokyo, read a paper " On some 

 zoological matters in Japan." He traced the gradual rise 

 of science in Japan from beginnings which could be traced 

 back as far as the ninth century. He then gave a sketch 

 of the present condition of zoological science in Japan, 

 referring amongst other points of interest to the beautiful 

 new marine zoological station at Misaki, near Tokyo, and 

 to the great richness of the marine fauna of the neigh- 

 bourhood. 



Mr. Stanley Gardiner read a paper on " The building of 

 atolls,'' suggesting that the depths at which corals and 

 nuUipores live is due to the extent to which light can 

 penetrate sea water, the food of corals being derived 

 entirely from the commensal &\g:v. The atoll-reef was 

 then shown to have arisen from a pinnacle on the top of 

 a dome-shaped mound, formed on an elevation of the 

 ocean floor, wliich,had been built up by the remains of 

 deep sea animals. 'It was then urged that these pinnacles 

 broaden by the addition to their edges of buttresses, etc., 

 on a talus slope supplemented by the solution of their 

 interior parts. 



Wednesday, August 2iTH. 



A general meeting of the (Jongress was held in the 

 morning (Prof. Dr. F. E. Schulze in the chair), when 

 Prof. Yves Delage opened a discussion on the position of 

 sponges in the animal kingdom. The discussion was 

 continued by Mr. E. A. Minchin, who remarked that there 

 was no group of organisms whose systematic position is so 

 much disputed, at all periods as well as at the present day. 

 Up to the end of the first half of the nineteenth century 

 it was still a matter of dispute if sponges were plants or ani- 

 mals ; this controversy was laid to rest by the discovery of 

 cilia by Dujardin (1841), and Dobie (1850), as well as by 

 the subsequent researches of Lieberkuhn and Carter. The 

 animal nature of sponges was thus established, but their 

 position in the animal kingdom was still uncertain. In 

 conclusion, Mr. Minchin said that the larval development 

 showed that sponges could not be considered Ca4ente- 

 rates. Such a comparison must start either from the 

 larv;r or the adults. If based on the larviu, then 

 neither the architecture nor the composition of the adults 

 were in any way comparable. If based on the adult 

 structure, then the larval development of sponges was 

 altogether anomalous, and not simflar to any other known 

 development, since the ectoderm assumed an internal 

 position, and became surrounded by the endoderm. The 

 most probable view was that sponges were descended from 

 Choano-flagellate Protozoa, since collar cells were not 

 known to exist except in these groups. 



The discussion was continued by Prof. Haeckel, who 

 was in favour of the Ccclenterate theory ; Dr. Vosmaer, 

 who believed that " we cannot yet answer the question 

 about the position of sponges," but suggested that " if we 

 have to classify, we must either bring them to a separate 

 group of the same value as the Metazoa, or consider them 

 as Metazoa, but forming a separate class, like Ccrlenterates, 

 Echinoderms, etc." ; Mr. Saville Kent, who urged that 

 " this vexed problem of sponge affinities should be fairly 

 approached and examined from a protozoic as well as from 

 a calenterate basis, and that those undertaking the task 

 should familiarise themselves with both the collar-bearing 

 flagellates and the corresponding sponge elements in their 

 living state." 



In the afternoon Prof. Ewart exhibited and made remarks 

 upon a very interesting series of slides, showing photographs 

 of Hybrids between the Horse and the Somali Zebra. 



Mr. Durham, for Prof. Kanthack and himself, read a 

 paper on Tsetse Disease. 



Tsetse disease, or N'gana, is one of the many scourges of 

 South Africa. Bruce discovered that the cause of the 

 disease is a parasite belonging to the flagellated protozoa 

 and the genus Tnipan-ixuma. According to Bruce's observa- 

 tion, the fly merely acts as a carrier. If it feeds on the 

 blood of an infected animal, and again feeds within two or 

 three days upon a healthy susceptible animal, it com- 

 municates the disease. .\ fact of importance in the 

 dissemination of the disease is Bruce's discovery that the 

 fly is viviparous ; the mother flies have to feed frequently 

 in order to nourish their young. Bruce has further shown 

 that the blood of certain of the wild^nimals of the " fly 

 districts' may contain the parasite (e.fi., the Koodoo). 



At the instance of the Royul Society, the living parasite 

 was brought over to this coimtry, where a large number of 

 experiments have been made. 



The inoculation with the parasite not only gives rise to 

 a fatal issue in the horse, ass, ox, goat, dog, and such 

 domesticated animals, but is also fatal to mice, rats, etc., 

 including the hedgehog. The guinea-pig is able to with- 

 stand the infection for several months in some cases. 



So far we have no means of curing the disease when it 

 has once begun, nor have we any means of preventive 

 inoculation or salting. Some drugs, like arsenic, help to 

 prolong the life of the animals, but the end is always fatal. 

 Prof. Cossar Ewart has, with the true scientific spirit, 

 allowed certain of his valuable zebra hybrids to be inoculated 

 with the tsetse disease in order to see whether they will 

 show a degree of refractoriness which the zebra must 

 possess, in that it is capable of living in the fly-infested 

 districts. It is too early to make any statement with 

 regard to these animals, since they have only been recently 

 inoculated. They have all shown signs of illness, and the 

 parasite has been found in their blood. Whether they 

 recover eventually must be left to the future to decide. 



A question was asked as to whether man was refractory, 

 in reply to which Mr. Durham said that all the evidence 

 that we have in regard to the susceptibility of man is 

 entirely negative. Man is bitten by the fly, and accidental 

 scratches and cuts have been incurred during experimental 

 investigation, which would have been sufficient to have 

 communicated disease had man been susceptible. 



Prof. Pelseneer, of the University of Ghent, expressed 

 his views on uniform orientation of the figures in zoological 

 papers, showing of what great advantage it would be if, in 

 papers treating on the same objects, all the figures could 

 be arranged in the same way, the left side of the animal, 

 for instance, being always on the left side of the figure, 

 and the same abbreviations being used for the same 

 organs. 



Thcbsday, August 25th. 



An interesting discussion was held in the morning on 

 the " Origin of Mammals." The debate was opened by 

 Prof. Seeley (London) and Prof. Osboin (New York). 



Prof. Seeley showed that the Theriodont division of the 

 Anomodonts approached the mammalia in the characters 

 of the teeth and the very small size of the quadrate bone ; 

 while, on the other hand, they suggested affinities with the 

 Labyrinthodont reptiles in the presence of such cranial 

 bones as the supratemporal, and of intercentra in the ver- 

 tebra. Although the parts of the pectoral and peh-ic 

 girdles bore a close comparison with those of the Mono- 

 tremes, and although in many Theriodonts the skull was 

 typically mammalian in form, the mandibular ramus never 

 consisted of a single piece as in mammals. The Anomo- 

 donts were not the parents of mammals, but a collateral 

 and closely related group ; and the common parent of both 



