ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 861 



particles ; from wliat we know of muscles and cilia we may assume 

 that the proximate cause of the change of form of iuotagmata is a 

 change of their water-contents ; so that the cause of contraction is a 

 peculiar process of swelling. The further analysis of the mechanism 

 is a question for the j^hysicist, and the chemist must consider the 

 problem of how the change in the water-contents of inotagmata are 

 occasioned. " It is, however, in the present state of our knowledge, 

 idle to express any further opinions upon the subject." 



Power of Reducing Silver possessed by Animal Protoplasm.*— 

 Dr. O. Loew in conjunction with Dr. Th. Bokorny having already 

 shown that living vegetable protoplasm has the proj)erty of reducing 

 silver, now extends these observations to animal protoplasm. 



The excised kidneys of frogs and toads were placed in 60-100 cm. 

 of a particular silver solution described by the author, with the ventral 

 side upwards ; after being kept in the dark for fifteen minutes it was 

 found that the ventral surface of the gland was traversed by black 

 lines ; after a sojourn of two hours in the solution the colour was 

 intensified and more of the kidney affected ; this most striking reaction 

 can be only seen in the living condition. It is impossible, however, 

 to extract from the kidneys any reducing substance, though it is clear 

 from the following experiment that such a substance must exist ; the 

 urine of six frogs was extracted by means of a pipette and placed in 

 the dark for twelve hours with some of the silver solution ; at the 

 end of this time a number of grey specks were observed at the bottom 

 of the vessel ; these were collected and treated with ammonia, and 

 dissolved ; they imparted to the solution a dark opalescent colour as if 

 l>roceeding from a feeble reduction. 



In Sxnrofjyra, however, where the reaction is extraordinarily 

 intense, it could be shown by direct exj)eriment that the oxygen of 

 the reduced silver oxide was taken up by the albumen. 



Foetus of Gorilla. t — J. Deniker describes a foetus of the gorilla 

 in the fifth month. In almost every respect it approaches closely to 

 the form of the human foetus at the same age. The hand diflers 

 from that of the adult gorilla by the greater proportionate length of 

 the fingers. The leg is cylindrical, without the projection of the 

 calf evident in the human fcetus. The cephalic index is 86 • 2. 



Influence of Magnetism on the Development of the Embryo.J 

 — Prof. C. Maggiorani, during the process of artificial incubation, 

 exposed a number of eggs to the influence of powerful magnets. A 

 similar set of eggs, being hatched in the same manner, but kept away 

 from all magnetic action, served as a check. Cases of arrested 

 development were four times more numerous in the first group than 

 in the second. Microscopical examination showed that the steriliza- 

 tion of the germs was probably due to an intense vascularization of 

 the yolk-sac. 



♦ Pfliiger'fl Arch. f. d. gcsammt. Physiol., xxxiv. (1881) pp. 596-601. 

 t CoinptOH KondiiH, xeviii. 'IHSl) pp. 758-0. 



I Atti R. Afcad. Liucci, Trana., viii. (ISS4) pp. 274- !». Cl. Jourii. of Science, 

 vi. (1884) pp. 600-1. 



