ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
295 
ostrich, and which correspond to the operculum described by T. J. Parker 
in embryos of the Kiwi, also occur more or less developed in Sterna 
minuta, Corvns cornix , G. frugilegus, CEdicnemus crepitans, AEgialitcs 
hiaticula, and Anas domestica. 
Veins of Head and Heck in Reptiles.* * * § — Herren 0. Grosser and 
E. Brezina find the simplest state of affairs in lizards. In these the 
cardinal vein persists in the region of the trigeminal ; and further back 
its place is taken by the F. capitis lateralis. In snakes there is a lateral 
vessel in the whole region of the head. In both snakes and lizards there 
is an internal jugular, but this is absent in Chelonians. The crocodiles 
are most divergent, having only that portion of the V. capitis lateralis 
which lies lateral to the vagus group, and two jugulars, one superficial, 
and the other comparable to the internal jugular. The fundamental 
system probably consists of a median longitudinal vein falling into three 
portions, and three transverse veins running between the main divisions 
of the brain. 
Regeneration of Crystalline Lens in Triton.f — Herr Erik Muller 
has repeated the experiments of Gustav Wolff j; on this subject in order 
to satisfy himself that regeneration occurs after complete extirpation. 
His results completely confirm those of Wolff, that is, the lens is rapidly 
regenerated after extirpation, the process taking place as follows : — The 
inner layer of the iris becomes thickened, and loses its pigment, the 
cells nearest the margin of the outer layer partake of the same change, 
and by the continued growth of these cells a new lens is formed. 
The differentiation of the lens from the iris-outgrowth occurs in the 
same way as that in which the lens is originally formed in develop- 
ment. 
Egg-Cases of Port Jackson Sharks.§ — Mr. E. R. Waite describes 
the hitherto unrecorded egg-case of Cestracion galeatus, which differs 
conspicuously from that of C. Philippi in having long tendrils. The 
eggs of the latter species are found wedged firmly, crown outwards, 
among the rocks ; those of the former are entangled by their tendrils to 
seaweeds. Both have external spirals, but these are diminished and 
probably of little use in C. galeatus, where they have been replaced by 
the tendrils, which may be 90 inches in length. 
£. Histology. 
Stomach Giands of Vertebrates. || — Dr. A. Oppel notes that the 
stomach glands of Vertebrates are divided into those of the fundus and 
those of the pylorus. The former are again distinguished in lower Ver- 
tebrates as basal cells and neck cells, while in Mammals there are cover- 
ing cells ( Belegzellen ) and main cells ( Hauptzellen ). His theory is that 
the Haupt cells of Mammals correspond to the neck cells of lower Ver- 
tebrates, and the Beleg cells to the basal cells. 
* Morphol. Jahrb., xxiii. (1895) pp. 289-325 (2 pis.). 
t Arch. f. Mikr. Anat., xlvii. (1896) pp. 23-33 (2 pis.). 
X Biol. Centralbl., xiv. (1894). 
§ Journ. Linn. Soc. Zool., xxv. (1896) pp. 325-9 (1 pi.). 
|| Auat. Anzeig., xi. (1896) pp. 596-601 (7 figs.). 
