ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
541 
necting stem. The funicle is enclosed in a thick chitinous capsule, 
which is identical with the so-called central disc of the compound fronds 
of numerous Monograptidae. The central disc is surrounded by a ver- 
ticil of oval capsules, which number from four to eight, and probably 
still more. The vesicles appear to have been organs of reproduction 
comparable with the gonangia of recent Hydrozoa. The author thinks 
that the colonial stock was carried by a large air-bladder, to the under 
side of which the funicle was attached. By the possession of a pneuma- 
tocyst and the arrangement of the reproductive organs at the bases of 
the stipes, the colonial stocks of Diplograptus have a general similarity 
to those of certain Siphonophora, while the chitinous structure of the 
hydrothecae and gonangia can only be referred to the Sertularians. “ It 
thus becomes evident that the genus Diplograptus, like so many Palaeo- 
zoic fossils, has the combined properties of different groups, thus giving 
valuable hints in regard to the common ancestors of these groups.” 
Grafting Experiments on Hydra.* * * § — Herr G. Wetzel has made 
numerous extraordinary experiments with Hydra , e. g. grafting the head 
of one on the foot of another, and the net result is a demonstration 
of the strong tendency to restore the normal forms. The fusion of two 
grafted forms, even if their poles be reversed, is remarkable, but the 
subsequent regenerative processes corroborate the theory of definite 
polarities. 
Sub-epithelial Nerve-plexus of Ctenophora.t — Herr A. Bethe has 
made a fresh examination of the nerve-plexus which has been the subject 
of so much controversy. He substantiates in almost all details the con- 
clusions of R. Hertwig, and expresses his opinion that the nerve-plexuses 
as seen in Ctenophores present us with one of the oldest and most 
primitive forms of the nervous system, and that isolated nerve-paths are 
a later acquisition. 
Porifera. 
Two new Hexactinellida.J — Dr. I. Ijima describes what appears to 
be a new species of Euplectella from Sagami Bay. E. marshalli , as the 
new species is called, has a body of the shape of a lamp chimney, and 
may be provided with prominences which give a very corrugated appear- 
ance to it. In its spicules it appears to closely resemble E. oweni. A 
new species of Hyalonema, which is called H. ovatum, is also described 
from Sagami Bay. It would appear that this species has been con- 
founded with young specimens of H. apertum. 
Protozoa. 
Recent Theories on Cell Nuclei. § — Dr. A. Labbe reviews the recent 
theories in which the nucleus of the Protozoa is homologised with that 
of the cells of the Metazoa. With the exception of the Sporozoa, the 
Protozoa differ most importantly from the Metazoa in that the nuclear 
membrane persists during mitosis. Critically revising the work of 
* Arch. f. Mikr. Anat., xlv. (1895) pp. 273-94 (1 pi.). 
t Biol. Centralbl., xv. (1895) pp. 140-5 (2 figs.). 
% Zool. Mag., vii. (1895) pp. 93-6. 
§ Arch, Zool. Exper. et Gen., iii. (1895) pp. x.-xiv. 
