ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
185 
is to be referred to a reaction of the organism to external influences 
(bionomic conditions) to which the individual was exposed during its 
life-time. 
(2) Similar parents produce similar offspring. 
(3) If there are differences already present in the germs, the cause 
must be found in the parents ; it is a case of inheritance. A spontaneous 
germinal variation, without a corresponding influence on the parents, is 
impossible. 
(4) The possibility of the inheritance of acquired changes must be 
granted. 
Relationship of Amphioxus and Balanoglossus.* * * § — Mr. E. W. 
MacBride compares the threefold origin of the coelom in Amphioxus 
with that in Balanoglossus. The trunk coelom becomes divided into 
separate muscle segments, which are differentiated into a dorsal mus- 
cular and a ventral thin-walled portion. The “ collar coelom ” undergoes 
a similar differentiation, but the two portions do not for a long time 
become constricted off from one another ; and even when this occurs, the 
ventral part does not become confluent with the ventral part of the trunk 
coelom. “ The ventral part of the collar coelom grows back externally to 
the trunk coelom, forming two ventral lateral ridges, which reach some 
little distance behind the last gill-slit which is formed.” These ridges 
are really the first rudiments of the atrial folds, and the contained coelom 
gives rise to the ventral muscle of the atrial cavity. “ Now in Balano- 
glossus the hinder end of the collar extends over and covers the first gill- 
slit, and the suggestion of Bateson that this represents the first beginning 
of the formation of an atrium like that of Amphioxus is borne out by 
the facts just narrated.” Mr. MacBride also criticises very adversely 
Lwoff’s contention that only certain cells of the gastrular invagination 
are truly endodermic. 
A Japanese Amphioxus.f — 'H. Nakagawu describes a species of 
Amphioxus found in abundance at Amakusa, Kyushyu. Its “formula” 
as to segments does not agree with that of any of the nine species noted 
by E. A. Andrews. 
Tailless Batrachians of Europe. t — Mr. G. A. Boulenger has pub- 
lished through the Ray Society the first part of a description of the 
tailless Batrachians of Europe. There is a very interesting introduction, 
dealing with the classification, external characters, integument, dermal 
secretion, skeleton, viscera, habits, voice, pairing and oviposition, sper- 
matozoa, eggs, development and metamorphosis, tadpoles, hybrids, and 
geographical distribution. The rest of the volume discusses the Disco- 
glossidae and Pelobatidse. There are charming plates by Mr. P. J. Smit, 
and abundant excellent figures by Mr. J. Green. The second part of 
this valuable addition to zoological literature is to follow in a few 
months. 
Habits and Life-History of Frog.§ — H. Eischer-Sigwart has pub- 
lished his note-book of observations on Bana fusca. He discusses the 
* Proc. Cambridge Phil. Soc., ix. (1897) pp. 309-13. 
t Annot. Japon. Zool., i. (1897) pp. 125-32. 
X Ray Society, 1897, part i., 210 pp., 10 pis., and 76 figs. 
§ Vierteljahrsckr. Nat. Ges. Zurich, xlii. (1898) pp. 238-316 (1 pi.)- 
