ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
615 
primitive than in higher forms. The vesicular epithelial tissue of 
Sigalion and other Annelids — a tissue which serves for the fixing of the 
supporting elements of the nervous system, and also for the insertion of 
the musculature — corresponds to the notochord of Amphioxus. It may 
be remembered that according to Lwoff the notochord of Amjphioxus 
arises from the ectoderm, differentiating from a rudiment from which 
nervous system and lateral musculature also develope. The above- 
mentioned supporting tissue of Annelids is also ectodermic. It has a 
developmental, histological, and functional correspondence with the 
notochord of Amjphioxus. 
B. INVERTEBRATA. 
Mollusca. 
Land and Fresh- water Mollusca of New Zealand. 4 " — Messrs. C. 
Hedley and H. Suter have published a reference list of these Molluscs 
which should be useful to students and residents. They remark that 
as the New Zealand fauna becomes better known, its insularity stands 
out more prominently. One by one foreign genera that have been 
falsely imposed on the fauna by the negligence of collectors or the 
mistakes of authors, have been eliminated. All the species are now 
known to be strictly endemic, and the relation to North Australia has 
been shown to be based on fictitious evidence. One hundred and eighty- 
four species are catalogued. 
a. Cephalopoda. 
Coloration of Integument of Cephalopoda.f — Dr. L. Joubin finds 
that the development of the chromatophore commences with the invagi- 
nation of an ectodermic cell into the mesodermic connective tissue; it 
gradually sinks in, and ends by forming the base of an ectodermic 
depression from which it, finally, becomes detached. It then becomes 
connected with some mesodermal connective cells which are applied to 
its surface ; it grows, dilates, and disposes its contents in two zones, the 
inner of which is the denser. The nucleus, which is at first distinctly 
visible, becomes less and less well marked as the chromatophore becomes 
complete. 
Meantime, the mesodermal cells increase rapidly in number, and 
form a corona of cells for the ectodermic cell, which is now lenticular 
in shape. The peripheral cells become contractile and soon fibrillated, 
when they serve to fix the principal cell to the surrounding tissues and 
maintain it perfectly distended, so as to allow of the play of the coloured 
protoplasmic contents. This double transformation of the peripheral 
cells into muscular, and thence into connective fibres, explains the two 
opposing views that have been held as to the constitution of the chro- 
matophore. It is, at the same time, clear that the fibres, even during 
their muscular phase, have no action on the coloured protoplasm, which 
is animated only by amoeboid movements of expansion. 
In studying the coloration of living animals, the author applies a 
process of staining which has, as yet, been only used for Fishes and 
