( 575 ) 

 SUMMAEY 



OF CUERENT RESEARCHES RELATING TO 



ZOOLOOY AND BOTANY 



(j)rincipally Inverfehrata and Cryptogamict), 



MICROSCOPY, &c., 



INCLUDING ORIGINAL COMMUNICATIONS FROM FELLOWS AND OTHERS* 



ZOOLOGY. 



A. GENERAL, including Embryology and. Histology 

 of the Vertebrata. 



Mesoblast of the Vertebrata.j — Professor 0. Hertwig is of 

 opinion tliat this layer is not split oflf, but is folded off from the 

 endoblast, and that this occurs on either side of the blastopore. The 

 complete separation of the mesoblast from the endoblast happens 

 some time after its development. The bands of cylinder-epithelium 

 below the primitive groove or chorda-endoblast begin to be folded 

 in, and give rise in time to a solid rod of cells (the notochord). 

 Meantime the parietal and visceral lamellaB of the mesoblast unite 

 below this layer, and separate from it and from the enteric endoblast. 

 The large polygonal cells of the latter now press more and more 

 towards the middle line, and finally fuse with the lower surface of 

 the notochord. It follows, therefore, that the closure of the per- 

 manent enteron on its dorsal side, the separation of the mesoblastic 

 sacs from the endoblast, and the development of the chorda dorsalis 

 are processes in development which are very intimately connected 

 with one another. 



Embryonic Sternum.t — Students of Professor W. K. Parker's 

 monograph on the shoulder-girdle and sternum should read an essay 

 by Herr G. Euge, on the development of the breast-bone and its con- 

 nections in man, which has just appeared. 



Development of Parrots.§ — Dr. Max Braun continues his important 

 studies, which, notwithstanding the title, are not confined to parrots. 



* The Society are not to be considered as 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 the 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 and 

 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 Jen. Zeitschr. f Naturwiss., xiv. (1881) Suppl. Heft, pp. 110-13. 



% Morph. Jahrb. (Gegenbaur), vi. (1880) pp. 597-602. 



§ Arbeit. Zool.-Zoot. Inst. Wiirzburg, v. (1881) pp. 205-341 (5 pis.). 



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