PHYSICS AND NATURAL HISTOEY OF GENEVA. 197 



Professor Claparcde read a memoir on the circulation of the blood in 

 arachnidsc of the genus lycosa. Tbe examination of this circulation conducts 

 the author to a very unexpected result : that in these animals the blood, in 

 almost tlie whole of the heart, moves from front to rear, contrary to what takes 

 place in all the arthropods hitherto studied. The memoir of M. Claparede hav- 

 ing been published in the previous volume of oin- collection dispenses with the 

 necessity of entering into the further details of this interesting investigation, 

 which, besides, it would be difficult to understand Avithout plates. The same 

 naturalist presented another memoir in which he sets forth the result of his in- 

 teresting researches made at Port Vcndres, durhig the summer of 1S63, on the 

 anatomy and classification of marine annelids. He first occupies himself with 

 a type which has not been studied heretofore except in a manner probably very 

 imperfect, that of the polyophthalmaj, which forms among the chetopods an in- 

 termediate link between the oligochetaj and the polychetai. He next examines 

 the annelida?, degraded from the family of the terebellacaj, in which the disap- 

 pearance of the vascular system is accompanied by the formation in the general 

 cavtiy of the animal, of a liquid holding in suspension red globules, very similar 

 to the corpuscles of the blood of mammifers, and thrown into continual move- 

 ment to and fro by the contractions of the walls of the body. Lastly, he passes 

 to the examination of the family of syllidaj, of which the species present some 

 the normal and others the alternating generation. Among more than twenty 

 species pertaining to this family, and found by him at Port Vendres, one species 

 only was already known. This memoir, accompanied with plates, is inserted 

 in the present volume of memoirs of the society. 



M. Victor Fatio read a memoir on the reproductive male apparatus of the ac- 

 centor alpinus, one of the pretty sparrows of our Alps. In the spring, at the 

 approach of rutting time, its testicles acquire an enormous development, attain- 

 ing a volume of about one-third of that of the entire trunk. Their different 

 vessels, instead of opening directly into the cloaca, are wound upon themselves, 

 and form on the sides of the anus two large balls which hang beneath the tail 

 in pouches covered by the skin. On issuing from these balls, the vessels in 

 question are directed towards the common vestibule, and terminate at the ex- 

 tremity of a small sexual papilla. In autumn all this temporary development 

 disappears. Doctor Dor read a memoir on tlie physiological effects of the bean 

 of Calabar, (physostigma venenosa.) Studied specially in its efiPects on the 

 eye, this substance produces contraction of the pupil, and occasions a sort of 

 cramp of the accommodator muscle. In this double relation it acts as an anta- 

 gonist of the atropima. Professor Valentin presented a note on the stretching 

 of the motor nerves. This stretching, by producing elongation of the fibrillous 

 sheath of Schwan, must nari-ow the diameter, and thus occasion, jnohahly, a 

 certain degree of compression of the nervous pulp which it envelopes * M. 

 Valentin has sought to measure the effects of the stretching in question, and 

 that by help of a measuring apparatus at once rotary and graphic, and of a 

 slight current of induction, as a means of excitation of tbe nerves examined. 

 The same physiologist made a communication on the effects of the separation 

 of the motor nerves from the nervous centres. He has ascertained: 1st, that 

 a discontinuity of one demi-millimctre suffices to produce all the effects resulting 

 from the separation in question, which excludes the idea that the nervous force 

 can act at a distance, as in induction ; 2d, that when the two separated ends 

 of the nerve are examined with the microscope, it is found that the peripheric 

 portion presents only degenerated fibres, while the end attached to the nervous 

 centres is composed only of fibres perfectly normal. For the great sympathetic 

 the effects are different, on account of the anastomoses of the peripheric end. 



* We say ■probably, because if the elongation of the nervous substance is proportional to_ 

 that of the sheath which envelops if, there will not be compression, but a stretching only of 

 the nervous pulp enveloped. 



