( 23 ) 



SUMMAEY 



OF CURRENT RESEARCHES RELATING TO 



ZOOLOG-Y AND BOTANY 



{])rincipally Invertebrata and Cryptogamia), 



MICROSCOPY, &c., 



INCLUDING OKIGlNiL COMMUNICATIONS FEOM FELLOWS AND OTHERS.' 



ZOOLOGY. 



A. GENEBAL, including Embryology and Histology 

 of the Vertebrata. 



Photographs of the Developmental Process in Birds.f — C. 

 Kupffer and B. Benecke give fifteen photographic plates of the 

 embryos of birds, with full descriptions, the outlines of the photo- 

 graphs being drawn on transparent paper, on which the necessary- 

 lettering is placed. A full description of the photographic apparatus 

 is given, and it is stated that osmic acid was found to give to the embryos 

 a colour suitable for photographic reproduction. When whole embryos 

 are reproduced, the amplification is ten, and when one or other end 

 only is j^hotographed, it is twenty times. Some of the photographs are 

 particularly good, and the tracings form admirable diagrammatic 

 representations of the different relations of the parts. An important 

 fact to which attention is drawn is, that within the limits of one 

 species variations have been found to be much more marked in the 

 earlier than in the later periods. 



Development of the Paired Fins of Elasmobranchs.| — Mr. F. 

 M. Balfour states that in Scyllium these arise as slight longitudinal 

 ridge like thickenings of the epiblast, and that in Torpedo the ante- 

 rior and posterior are on either side transitorily connected together 

 by a line of columnar epiblast cells. Later on, the fins become a 

 ridge of mesoblast covered by epiblast ; the embryonic muscle-plates 

 grow into the bases of the fins, and form two layers, while in the 

 intermediate indifferent mesoblast changes begin to be set up, which 

 give rise to the cartilaginous skeleton. There is thus formed in the 

 fin a bar which springs at right angles from the posterior side of the 



* The Society are not to be considered responsible for the views of the 

 authors of the papers referred to, nor for the manner in which those views 

 may be expressed, the main object of this part of tlie Journal being to present a 

 summary of the papers as actually published, so as to provide the Fellows with 

 a guide to the additions made from time to time to the Library. Objections aud 

 corrections should therefore, for the most part, be addressed to the authors. 

 (The Society are not intended to be denoted by the editorial " we.") 



t Nova Acta Acad. Cses. Leop.-Carol. Germ. Nat. Cur., xli. i. (1879) pp. 149-96 

 (1 pi. and 15 photos.). 



X Proc. Zool. Soc. Lend., 1881, pp. 656-71 (2 pis.). 



