ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 509 



spindle pole only. Even if the view be taken that the reduction takes 

 place at the second division, this does not correspond to Boveri's scheme, 

 since the spindle threads disappear after the first division, and a nuclear 

 membrane is developed and new spindle threads are formed before the 

 second division. 



Phagocytic Absorption of Ova by Follicle Cells in Fasting 

 Newt.* — Ch. Perez describes this interesting phenomenon in a newt, 

 Molge marmorata Dum. et Bibr., which had fasted for four months. 

 Besides ova in process of normal growth, there were others of an orange 

 colour (identical with that of the adipose bodies) which were obviously 

 in process of being absorbed by those very elements which serve 

 normally for their nutrition. This is a good example of a phase of 

 internal struggle which could hardly have leen predicted, even as a 

 possibility, from what is known of the normal conditions. 



Parthenogenetic Development of Lamprey's Ova.f — E. Bataillon 

 has succeeded in evoking segmentation on to the blastula stage in un- 

 unfertilised ova of Petromyzon planeri, by placing them in a 5-6 p.c. 

 sugar solution or in a salt solution. The removal of water by the 

 solutions is regarded as the effective stimulus inducing cleavage. 



Experiments on the Developing Ova of the Frog.| — Georges 

 Bohn records some interesting effects of light on the development of 

 the ova of Rana temporaria, e.g. the general inhibitive effect, com- 

 parable to the results of radium-influence. The advent of meta- 

 morphosis appears to be in great part due to nutritive influences. 

 Green algse may have a more or less important influence on . the 

 development of the ova ; there is sometimes a kind of symbiosis, the 

 occurrence of which may give rise to a kind of pcecilogony. 



Development of Human Milk Glands.§ — H. Eggeling describes 

 certain early stages in the development of the human mammary gland, 

 hitherto not very clearly known. His results prove that if we are not 

 to accept the ^view that the lacteal glands are sui generis, we must 

 regard them as homologous with sweat-glands. He is emphatically of 

 opinion that both have proceeded in different directions from a primitive 

 " merocrine " skin-gland. 



Development of Mandibular Articulation. || — Knut Kjellberg has 

 directed special attention to the -" meniscus " in the mammalian articu- 

 lation between the mandible and the squamosal. His observations on 

 various embryos lead him to accept the general hypothesis that the 

 articular and quadrate of Sauropsida are represented by the malleus and 

 incus in Mammals, that the articular when enclosed in the tympanic 

 cavity took with it a 'portion of the M. pierygoideus extermis, while 

 other considerable portions remained attached to the dentary and its 

 condyle, that the most posterior muscular portion is squeezed in between 



* Proc. Verb. Soc. Sci. Bordeaux, 1903, pp. 73-4. 



t Comptes Rendus, cxxxvii. (1903) pp. 79-80. 



t Op. cit., cxxxviii. (1904) pp. 1244-5. 



§ Ariat. Anzeig., xxiv. (1904) pp. 595-605. 



j| Morphol. Jahrb., xxxii. (1904) pp. 159-84 (8 fipe.\ 



