NA TURJi 



[SePTEMBEK 22, 1904 



Mr. G. P. Bidder pointed out the great economic import- 

 ance of Looss's researches. He stated that experts now 

 believed the majority of cases in the Cornish tin mines were 

 due to infection of the bare shoulders, arms and hands, 

 through coming into contact with some polluted surface 

 in the mine. Against such infection, cleanliness in feeding, 

 which has been recommended as the principal precaution, is 

 of no avail. The question is a serious one, as the disease 

 is grave, and there are half a million men working in our 

 coal mines. Though as many as 80 per cent, of the men 

 were affected in some Continental mines, the disease does 

 not at present e.xist in British collieries ; but in many of 

 these there are those conditions of temperature and humidity 

 which would be favourable to its propagation. 



Prof. Simmers (Cairo) commented on the paper from an 

 experience of thousands of cases. Nothing resembling the 

 " miners' bunches " which have been described as occurring 

 in Cornwall has been met with in Cairo. Looss's experi- 

 ments on puppies point to a definite toxic effect on the tissues 

 penetrated by the larvae. A remarkable feature about the 

 adult parasite is the absence of any wounds or bleeding on 

 the intestinal wall to which it adheres. The muscular 

 mouth of the worm appears to draw up the tissues into a 

 sort of bell, and at the same time to secrete into the blood 

 some substance which has the power of breaking up the 

 constituents of the blood, so causing the peculiar aneemia. 



Prof. G. N. Calkins gave to the section an account of 

 his work on Cytoryctes variolae, Guarnieri, the organism of 

 small-pox. After the inoculation of a rabbit's cornea with 

 vaccine virus, Guarnieri (1892) found in the cells peculiar 

 homogeneous structures of diverse form and size, and re- 

 garded them as Protozoa. Pathologists, however, do not 

 accept this conclusion, as the " Guarnieri bodies " have no 

 apparent structure, and cannot be cultivated on artificial 

 media. Prof. Calkins considered these objections were dis- 

 pelled by the experiments of Wasielewsky (1901), who 

 vaccinated a rabbit with a small quantity of virus ; from 

 this a second rabbit was vaccinated, from the latter a third, 

 and so on until forty-seven had been successfully inoculated! 

 In all the rabbits the " Guarnieri bodies " were found, and 

 Prof. Calkins believes they had undergone growth and 

 multiplication — the attributes of a living organism. In 1902 

 Councilman discovered, in addition to the usual bodies in 

 the cytoplasm, peculiar and definite bodies in the nuclei of 

 skin-cells infected with small-pox. Prof. Calkins has 

 worked over this material (from fifty-five cases), and has 

 formulated a life-history. The first appearance of the 

 organism in the human skin is a minute homogeneous 

 spherule which enlarges and differentiates into two sub- 

 stances, one destined to give rise to the multiplication 

 elements, the other forming an enveloping matrix. The 

 organism increases in size until it is larger than the cell 

 nucleus. The gemmules repeat the cycle again and again, 

 thus giving rise to auto-infection of the vaccinia type. In 

 later stages the gemmules enter the nucleus, where they 

 develop into two kinds of structures, possibly male and 

 female gametocytes. From the latter a spor'oblast stage 

 arises, the sporoblasts increase in size, and ultimately give 

 rise to spores. Meantime, the nuclear membrane has been 

 ruptured and the sporoblasts liberated. The spores are 

 hollow spherules os/t in diameter. Spores may be found 

 scattered in the cytoplasm and in the nucleus, but it is only 

 in the latter that they can develop further. 



After Mr. J. J. Lister, F.R.S., had commented on the 

 apparent absence of a definite nucleus. Dr. S. Monckton 

 Copeman, F.R.S., mentioned that in a paper by Dr. Gustav 

 .Mann and himself (1898-9) practically all the features de- 

 scribed by Prof. Calkins are shown, but that their interpre- 

 tations are entirely different. They regarded the " Guarnieri 

 bodies " as masses of nucleo-proteid material which have 

 been extruded into the perinuclear space as the result of 

 specific irritation, and it is noteworthy that these bodies are 

 all found, in cases of inoculated variola or vaccinia, on the 

 side of the nucleus remote from the point of inoculat;on, 

 whereas the reverse might be expected if they were Protozoa! 

 Similar appearances have been described by Pfeiffer and 

 others in carcinoma, sarcoma, chicken-pox, and various 

 vesicular skin diseases, all of which diseases cannot be due 

 to the same specific agent. The specific zymotic disease 

 which in all respects — period of inoculation, progress, 

 affection of the skin and mucous membranes, production 

 NO. 1821, VOL. 70] 



of immunity, &c. — most closely resembles small-pox, viz. 

 enteric or typhoid fever, is now acknowledged to be a 

 bacillary disease, and there would seem to be reason for 

 believing small-pox to be due to an invasion of the system 

 by a similar organism. Dr. Copeman considers that the 

 small bacillus, which he demonstrated at the Liverpool 

 meeting, which stains with great difliculty and cannot be 

 grown on any of the ordinary laboratory media, represents 

 the specific virus of small-po.x and vaccinia. 



Dr. J. A. Murray, of the Imperial Cancer Research Fund, 

 read to the section a paper on the biological significance 

 of certain aspects of the general pathology of cancer. He 

 stated that both benign and malignant new growths increase 

 their characteristic parenchyma entirely from their own 

 resources, and there is no evidence of the transformation of 

 the original tissue into malignant tissue, although the latter 

 may be indistinguishable histologically from that among 

 which it takes its origin. The cells increase by division ; 

 amitosis does occur, but mitotic division is much more 

 common in fully developed tumours. Multipolar mitoses are 

 common. The active growth and extension of the malignant 

 tissue as manifested at the growing surfaces of a 

 malignant new growth, are effected by cell divisions which, 

 so far as they are mitotic, conform to the ordinary type met 

 with in early development. The number of chromosomes 

 entering the equatorial plate is constant in each species, and 

 they undergo the usual longitudinal splitting. Passing 

 from the growing margin towards the older parts of the 

 growth, it is seen that some of the mitoses are characterised 

 by the presence of bivalent chromosomes (heterotype), in 

 number half that found in the younger parts. These hetero- 

 types must be regarded as occurring late in the life-history 

 of the cells in which they are present. The analogy of 

 spermatogenesis suggests that the heterotype initiates .a 

 terminal phase in the life-history of the cancer cell as in 

 the spermatocyte. While studying the changes which occur 

 immediately after transplantation in a tumour of the mouse, 

 nuclear changes were observed which presented a close 

 similarity to a conjugation process. Subsequent observ- 

 ations (on more than 1000 tumours of all ages from three 

 different primary sources) have tended to confirm this in- 

 terpretation. Numerous secondary centres of growth are 

 always found around the periphery of older tumours, and 

 these secondary masses may in time outgrovv' that which 

 preceded them. It is suggested that the cells which con- 

 jugate are those which have passed through a reducing 

 division, but until the complete cycle is elucidated this must 

 remain only a working hypothesis. 



THE EVOLUTION OF THE HORSE.' 

 pROF. H. F. OSBORN referred to the three independent 

 lines of research being carried on by Profs. Ewart, 

 Ridgeway, and himself, and hoped that they would be able 

 to bridge the interval which at present existed between the 

 fossil, the historic, and the recent races of horses. He gave 

 an account of the explorations, begun three years ago, of 

 the American Museum, which were rendered possible by 

 a liberal gift from the Hon. W. C. Whitney. The object 

 of this research into the fossil history of the horse was to 

 connect all the links between the Lower Eocene five-toed 

 and the Lower Pleistocene one-toed horses, and to ascertain 

 the relations of the latter to the horses, asses, and zebras of 

 Eurasia and .'\frica. The first result obtained is the proof 

 of the multiple nature of the evolution of the horse during 

 the American Oligocene and Miocene periods. Instead of 

 a single series, as formerly supposed, there are five — one 

 leading to Neohipparion, the most specialised antelope-like 

 horse which has ever been found ; a second, of intermediate 

 form, probably leading through Protohippus to Equus. a& 

 Leidy and Marsh supposed ; a third leading to the Upper 

 Miocene Hypohippus, a persistently primitive, probably 

 forest- or swamp-living horse, with short-crowned teeth- 

 adapted to browsing rather than grazing, and with three 

 spreading toes ; this horse has recently also been found in 

 China. A fourth and fifth line of Oligocene-Miocene horses 

 became early extinct. This polyphyletic or multiple law is 



^ Abstracts of three addres 

 tion on .August 23. 



I in Section D of the British As 



