( 629 ) 

 SUMMAEY 



OF CURRENT RESEARCHES RELATING TO 



ZOOLOGY AND BOTANY 



(jprindpally Invertehrata and Cryptogamia), 



MICROSCOPY, &c., 



INCLUDING ORIGINAL COMMUNICATIONS FROM FELLOWS AND OTHERS.' 



ZOOLOGY. 



A. GENERAL, including Embryology and Histology 

 of the Vertebrata. 



Aspects of the Body in Vertebrates and Invertebrates.! — Under 

 the above title Prof. E. Owen has republished in a separate form his 

 essays on the conario-hypophysial tract, and on the cerebral homo- 

 logies in Vertebrates and Invertebrates, which have already been 

 noticed in this Journal.^ Having had the opportunity of making some 

 additions, he now directs attention to the work, among others, of 

 Cadiat on the development of the branchial clefts and arches. In 

 this paper is figured the extension of the fore part of the ali- 

 mentary canal in the direction of that region of the brain which, 

 at a later period, is occupied by the conario-hypophysial relics. " The 

 branchial chamber, with the pulsating vesicle and first rudiments of 

 gills, here repeat the branchial sac which receives the oral aperture 

 of the alimentary canal in the Ascidians, a structure which is the 

 condition of the deviation, in a higher step of the Life Series, of the 

 oesophagus from its primary course, and of its communication with 

 the precocious gill-chamber, which then becomes the vertebrate mouth, 

 retaining the closer resemblance to the Ascidian branchial sac in the 

 lowest (piscine) forms of the Vertebrata (Amphioxus)." 



Ancestral Form of the Chordata.§— The great difficulty that is 

 encountered in any attempt to point out a definite group amongst 

 Invertebrates most closely allied to the primitive Vertebrata is the 

 total absence of anything resembling so important and so early-formed 

 an organ as the Vertebrate chorda dorsalis. 



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

 authors of the papers referred to, nor for the manner ia 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 8vo, London, 1883, iv. and 48 pp. (11 figs.). 



X See this Journal, ante, p. 349. 



§ Quart. Journ. Micr. Sci., xsiii. (1883) pp. 349-68 (1 pi.). 



