SUMMARY OF CURRENT RESEARCHES 
RELATING TO 
ZOOLOGY AND BOTANY 
(principally invertebrata and cryptogamia), 
MIC BOS COPY, Etc. 
Including Original Communications from Fellows and Others .* * * § 
ZOOLOGY. 
VERTEBRATA: — Embryology, Histology, and General. 
a . Embryology. f 
Ancestry of Vertebrates. J — Prof. W. N. Parker calls attention to 
Mr. Willey’s recent work§ on Amphioxus, in which it appears that an 
excellent description is given of the habits, anatomy, and development of 
Amphioxus , while a special section is devoted to the Ascidians. Mr. 
Bateson’s division of the Hemichorda is accepted, and the forms which 
constitute the group are described and compared, while an account is 
given of the development of Tornaria and of the larvae of Echinoderms. 
The general conclusion to which Mr. Willey arrives is that “for the 
present we may conclude that the proximate ancestor of the Vertebrates 
was a free-swimming animal intermediate in organisation between an 
Ascidian tadpole and Amphioxus , possessing the dorsal mouth, hypo- 
physis, and restricted notochord of the former, and the myotomes, coelomic 
epithelium, and straight alimentary canal of the latter. The ultimate 
or primordial ancestor of the Vertebrates would, on the contrary, be a 
wormlike animal whose organisation was approximately on a level with 
that of the bilateral ancestors of the Echinoderms.” 
Succession of Teeth in Man.|| — Herr W. Dietlein has taken an 
average of 7500 individuals as to the time of the appearance of the 
permanent teeth. His table is as follows : — 
* The Society are not intended to be denoted by the editorial “ we,” and they do 
not hold themselves responsible for the views of the authors of the papers noted, 
nor for any claim to novelty or otherwise made by them. The object of this part of 
the Journal is to present a summary of the papers as actually published , and to 
describe and illustrate Instruments, Apparatus, &c., which are either new or have 
not been previously described in this country. 
f This section includes not only papers relating to Embryology properly so called, 
but also those dealing with Evolution, Development and Reproduction, and allied 
subjects. X Nature, li. (1895) pp. 433 and 4. 
§ ‘ The Ancestry of the Vertebrates,’ London and New York, 1894. 
|| Anat. Anzeig., x. (1895) pp. 354-7. 
