634 SUMMARY OF CURRENT RESEARCHES RELATING TO 



and the true paired olfactory areas have do relation to the neuropore. 

 Further, the view that it is merely a mechanical result of developmental 

 processes is confirmed hy the fact that similar swellings occur during 

 the closure of the lens-vesicle and the ear-vesicle. An examination of 

 the other vertebrates on which Kolliker based his view shows that the 

 conditions seen there are capable of a similar explanation, and that 

 there is no proof that Kolliker's interpretation is the right one. 



Development of Nasal Cavity in Amphibia. * — Dr. V. Hinsberg 

 finds that in Anura and Urodela the first rudiment of the olfactory plate 

 results from proliferation of the sensory layer of the ectoderm. The 

 superficial layer of the ectoderm takes no part in the process, and soon 

 disappears over the centre of the olfactory plate. The method of 

 formation of the olfactory lumen differs considerably from that obtaining 

 in Amniota, the olfactory plate fusing with the epithelium of the buccal 

 cavity while itself still a solid cell-mass. Later, the olfactory lumen 

 breaks through into the endodermal part of the mouth-cavity, and not 

 into the ectodermal as in Amniota. The method of formation of the 

 olfactory lumen differs in detail in the Anura and the Urodela. In 

 both the originally simple lumen becomes complicated by the develop- 

 ment of blind sacs, more elaborate in the Anura than in the Urodela. 



Dorsal Groove in Egg of Triton taeniatus.j— Dr. Paul Bbthig notes 

 briefly the various interpretations offered of this structure, the BiicJcen- 

 rinne of Hertwig, the sillon median of Bambeke, and figures a series of 

 sections made by himself. The sections entirely confirm 0. Hertwig's 

 view that the furrow marks the area in which the lips of the blastopore 

 fused together during the earlier stages of development. 



Function of Infundibulum in Larval Fish.4 — J. Bocke suggests that 

 the infundibulum in larval bony fish may serve as a sense-organ. He 

 finds that in eggs ascribed to the Muraenoidea, the cells in embryos of 

 three days old are of two distinct kinds, sense-cells and supporting-cells. 

 The former have large circular nuclei, and are furnished with a brush 

 of long cilia. When the embryos leave the egg-membrane, the infundi- 

 bulum is very distinct, and the sense-cells have become modified in 

 form, being now furnished with a peculiar crown, apparently formed 

 from the cilia of the earlier stage, the crown being borne on the pro- 

 truding conical tips of the cells. In this form the organ remains 

 constant till the critical period, and is believed by the author to be a 

 functional larval organ. It occurs in similar form in other pelagic 

 Teleosts, e.g. Scorpsena and Fierasfer. 



Lorenzini's Ampullae in Selachians.§ — W. Minckert finds that these 

 organs are developed from the basal layer of the epidermis in embryos 

 of Spinax and Acanthias, and are derived from groups of specialised 

 epidermal cells. They originate at the same time as the sensory canals. 



Development of Teleosteans. || — A. Swaen and A. Braehet publish 

 the second part of their work on the organs derived from the mesoblast 



* Arch. Mikr. Anat., Iviii. (1901) pp. 411-82 (2 pis. and 1 fig.). 



t Anat. Anzeig., xix. (1901) pp. 561-7 (5 pis.). 



} Op. cit., xx. (1901) pp. 17-20 (2 fig*.). § Op. eit.. xix. (1901) pp. -197-527. 



|| Arch. Biol., xviii. (1901) pp. 73-190 (8 pis.). Cf. this Journal, 1899, p. 571. 



