286 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
the gonads. In some species only are there tubular accessory glands, 
rudimentary in character. The essential structure is that of a series 
of more or less elongated tubes, simple or branched, debouching into a 
reservoir enveloped by the dorsal mesentery. From this reservoir an 
efferent duct leads to a short papilla on the dorsal anterior surface. 
The genital rudiment or primordium is found in a mass of spherical 
cells in the dorsal mesentery. Inter alia , he comments on the edibility 
of the genital organs. 
Histologically the reproductive organs in the two sexes are closely 
alike. There is, first, an external ciliated membrane, then follows a 
muscular layer with longitudinal fibres (sometimes absent) and (thicker, 
more internal) circular fibres, then a connective and fibrillar membrane, 
to which is apposed a basilar membrane bearing the germinal epithelium. 
Echinoderm Fauna of New Zealand.* — Mr. H. Farquhar gives a 
list of ninety species, including a large number of peculiar forms, which 
give the Echinoderm fauna of New Zealand a strongly distinctive cha- 
racter of its own. Its affinities are strongest with that of Australia. 
Only two Cricoids, dredged by the ‘ Challenger,’ have as yet been found 
in New Zealand seas, and they both extend beyond the area. Nearly 
all the Ophiuroids and most of the Asteroids are endemic, while all the 
Echinoids, except perhaps Goniocidaris umbraculum, occur elsewhere, a 
large number being widely ranging forms. The littoral Holothurians, 
on the other hand, are all peculiar to New Zealand. Omitting doubtful 
and deep-water forms, 58 per cent, of the recorded species of New 
Zealand Echinoderms are endemic ; 36 per cent, occur in Australia ; 
and only 6 per cent, have been found elsewhere and not in Australia. 
Coelentera. 
Nervous System of Siphonophora.f — Dr. Theodor Schaeppi has 
investigated the histology of several members of this group, with special 
reference to the nervous system. The paper does not lend itself readily 
to the purposes of an abstract, but the following are among the more 
striking of the contained observations. In the stem of Forslcalia and 
the Anthemodinse the author finds that the structure described by 
Korotneff and Schneider as the central nervous system is merely a pro- 
longation of the endoderm of the central canal. This central canal 
sends out short branches which come to lie immediately beneath the 
ectoderm, so that at these areas endoderm and ectoderm are in contact, 
the middle lamella being absent. On the dorsal and lateral areas of the 
stem the ectoderm consists of (1) epithelial muscle-cells; (2) ganglion- 
cells ; (3) the cells of the interstitial layer; while on the ventral surface 
it consists only of “ indifferent ” cells and of ganglion-cells. This ven- 
tral surface is also furnished with small projections formed by clusters 
of ectodermal indifferent cells resting directly upon the endoderm 
without the intervention of a supporting lamella. Other Siphonophora 
show some variation as compared with this type, but the absence of the 
middle lamella at certain points is very characteristic of all. Thus the 
structure described as a nerve-groove in Apolemia and Praya is not 
* Proc. Linn. Soc. N.S. Wales, xxiii. (1898) pp. 300-27. 
f Jenaische Zeitsohr. Naturwiss., xxxii. (1898) pp. 483-550 (7 pis. and 11 figs.). 
