374 SOCIETY OF PHYSICS AND NATURAL HISTORY OF GENEVA 



rupture of the sliell; but the embryo, instead of being- free, is enveloped in a 

 membrane or deiifovum, whence it afterwards issues, first as a larva with a cara- 

 pace, to be transformed secondly into a larva without carapace, and finally to 

 become a perfect animal. In the embryo, as in the adult, the circulation is 

 supplied by the existence of alternating- or amceabean corpuscles, which insinuate 

 themselves among- the organs, and are the eciuivalent of the corpuscles of the 

 blood in other animals. M. Claparede has extended his researches to the para- 

 sitic acari of the skins of divers of the liodcntia. He has observed that these 

 minute creatures have organs of attachment analogous but not homologous, a 

 fact which is favorable to the theory of the gradual transformation of species in 

 the sense of Darwin. A parasite of the Mas musculus presents an eg-g, a 

 deutovum and tritovum, a circumstance hitherto unobserved. According to M. 

 Alois Humbert, the analogue of the deutovum occurs in the myriapod Chilog- 

 natlms. It has been seen also in the Jtihts, and been named the pupoid body. 

 It exists likewise among the GJomeris, in wljich, like the egg, it is spherical. 



M. Claparede has occupied himself also with another acarus, the Tetranyclms 

 of the Linden. It is known that in a great number of articulata, the blastoderm 

 appears around the vitellus without previous segmentation. Now, in the Tcira- 

 wjclius the formation of the l)lastoderm takes place by the division, repeated 

 many times, of a primitive cellule placed at the surface of the vitellus. The 

 nucleus of the cellule is of doubtful origin ; it is probable that it constitutes the 

 germiuative vesicle. This cellule should be considered as a vitellus of forma- 

 tion wdiich constitutes a segment at the surface of a vitellus of ruitrition. Hence 

 the ovules of the Tetranyclms enter into the class of those of which the segment- 

 ation is partial. {Archives cles Sciences, d'C, t. xxxi, p. 104.) 



Besides these original researches, M. Claparede submitted to us statements of 

 the most striking advances which have been made in zoology and its kindred 

 branches. Thus, he drew our attention to the investigations of M. Stein relative 

 to infusoria, and to this unexpected conclusion, that the bourgeons of the verti- 

 celli are but an appearance resulting from the fact that a small individual has 

 become conjoined with another of greater size. He analyzed the publications 

 of M. Semper on the inferior animals which inhabit the coasts of the Philippine 

 islands, and the new work of Dr. Darwin on the modifications experienced by 

 animals in a state of domestication. He acquainted us with the recent ol)serva- 

 tions of M. Parkes on muscular labor, according to which this labor would coin- 

 cide, not with an oxidation of the tissue of the nuiscle, but with an augmenta- 

 tion of its voliune produced by a more energetic assimilation of the nitrogenized 

 substances with which the blood is supplied. M. Clajjarede explained (7tli 

 November) the ingenious researches of Prof. Max Schultzo on the structure of 

 the retina. According to this skillful micrographist, the two sorts of elements 

 which are found unequally distributed in the exterior layer fulfill difi'erent func- 

 tions. The rod-like organizations (bufonnets) serve for the perception of the 

 luminous intensity, while the cones are destined to distinguished colors. 



Dr. Henry Dor made known to us that calabarine, the eftect of wliich on the 

 pupil is the reverse of that of belladonna, acts as an antidote to strychnine. In- 

 paralyzing the muscles which depend on the will without abolishing the latter. 

 It may, therefore, be useful in tetanic aftections. The professor last named 

 gave his confirmation (2d April) to the fact, based on the investigations of Cra- 

 mer and Heynolds, that the part heretofore attributed to the iris in the function 

 of adjustment is completely null. It is the ciliary muscle alone which is in ])lay. 



Dr. Julliard the younger has had occasion to study a temtological case very 

 rare in the human species, namely, scironomelia, or a soldering together of the 

 two lower members. He presented to the society two photographs of the mon- 

 strosity, the subject of which lived some instants after Ijirth, and gave a descrip- 

 tion of the anatomical peculiarities of the case. 



Our vice-president, Dr. Lombard, read to us (2d April) the results of his sta- 



