ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
623 
more than two in one plane ; the stem-groups include tile-like pro- 
tective rounded flaps traversed by six vessels, gonophores, and special 
swimming-bells ; in the internodes are heteromorj)hous tentacles on 
small mouthless polyps. 
Prof. Chun describes in detail the principal swimming-bells, the 
groups on the stem and their various components. This type is the 
only Calycophorid as yet known in which between the older groups 
new stem appendages are secondarily interpolated. He explains the 
development of the secondary reniform stinging- knobs and the stages 
in the production of gonophores. Against Weismann and others he 
regards it as probable that the gonophores with medusoid structure are 
not retrogressive modifications of Medusm, but on the contrary, that in 
many Siphonophora (Rhizophysse and Physalise) free Medusae are 
formed in progressive evolution from sessile gonophores. 
Female Gonophores of Errina labiata.* — Dr. S. J. Hickson has 
been able to show that the ripe ovum of this Hydrocoralline is covered 
by layers of both ectoderm and endoderm ; this discovery confirms the 
accuracy of the diagrammatic figure of the female gonophore which the 
author has recently published. 
Lucernariidse of East Spitzbergen.f — Dr. G. Antipa finds that the 
three species of Lucernariidae collected by the Bremen Expedition at 
East Spitzbergen all present a character first noticed by Prof. Haeckel in 
Lucernaria ( Lucernosa ) bathypliila ; the gonads, instead of having a 
simple structure, are much more complicated ; each gonad consists of 
numerous separate genital saccules, which all form lobate glands ; each 
saccule is formed of numerous follicles which have their own sinus and 
duct. He proposes, therefore, to form Lucernosa into a distinct genus, 
and he gives detailed accounts of the structure of the three new species, 
which he calls L. Walteri, L. Kuhenthali , and L. Haeckeli. 
Nervous System of Hydra.J — Dr. R. Zoja gives a short summary 
of the results he has attained by the use of methylene-blue staining of 
living Hydrse. Under the cuticle two or more noduli may be seen in 
the area of one epithelio-muscular cell; they have a rounded central 
part, from which numerous fibres radiate out irregularly. These either 
disappear in the surrounding tissue, or coil spirally round fibres coming 
from other noduli, or become connected with other forms of fibres, or 
form chains. These chains have always a spiral fibrillar structure. 
There may also be seen rich and complicated coils of fibres, fine plexuses 
formed of the same fibres as those which surround the curved part of 
the epithelio-muscular cells. From the stinging cells there are given off 
rigid fibres, which generally radiate from one point. The author 
believes in the nervous nature of these various forms of fibres on 
account of their specific coloration, the similarity of the nuclei of the 
coils with the nuclei of the ganglion-cells described by Schneider, and 
on the account of their connection with the epithelio-muscular cells and 
the urticating capsules. 
* Zool. Anzeig., xv. (1892) pp. 237 and 8. 
f Zool. JB., vi. (1892) pp. 377-96 (2 pis.). 
j Zool. Anzeig., xv. (1892) pp. 241 and 2. 
