532 THE AMERICAN NATURALIST.  [VouL. XXXIII. 
evident. Abundant biological data are included in the paper. Dr. 
Weber proposes a new solution for the Plœæsoma enigma, restoring 
Ehrenberg’s P. Zynceum and recognizing Herrick’s P. denticulare. 
A. K. 
Trematode Anatomy.’ i has given an extended ac- 
count of the anatomy of certain avian trematodes. He describes 
a number of papillae upon the ventral surface of chinostomum spa- 
thulatum Rud., each traversed by a canal with granular contents. 
These structures are interpreted as the outlets of glands found in 
the adjacent parenchyma, though a direct connection of the two was 
not established. Similar organs were also observed on the ventral 
surface, on the suckers, on the dorsal side of the neck, and along the 
posterior margins of Ai/harzia polonica M. Kow. These “openings of 
the cutaneous glands” resemble very much the structures found by 
Nickerson upon corresponding regions of Stichocotyle nephropis, and 
interpreted -by him as cutaneous sense organs on account of their 
connection with ganglion cells in the parenchyma. The occurrence 
of sexual amphitypes in a number of species of the trematode genus 
Opisthorchis is also noted by the author. In parasites from the same 
host individual the two types of sexual asymmetry occur in about 
equal numbers. CAE 
The Corpus Luteum in the Pig and Man?’ has been the sub- 
ject of careful study by J. G. Clark. The origin of this structure 
has been a matter of long-standing dispute, some investigators main- 
taining that it arose from the connective tissue investment of the egg- 
follicle, and others that it came from the follicular epithelium. Clark’s 
observations are strongly in favor of its connective tissue ọrigin. 
Cessation of ovulation is shown to be not due to the disappearance 
of egg-follicles, but to a densification of the ovarian stroma, whereby 
the peripheral circulation of the ovary is so interfered with that the 
complete formation of the follicles is hindered. 
The Albatross Brachyura. — Miss Mary J. Rathbun describes 
(Proc. U. S. Nat. Mus., XXI, 1898) the brachyurous Crustacea col- 
lected by the fish commission steamer A/batross during a voyage 
1 Kowalewski, M. Studya Helmintologiczne, V, Rozprawy ot Aust mat, proyres 
T. xxxv, 61 pp., Tab. I, II, 1898. 
2 Clark, J. G. The Origin, Growth, and Fate of the Corpus Luteum as 
observed in the Ovary of the Pig and Man, The Johns Hopkins Hospital Reports, 
vol. vii (1898), No. 4, pp. 181-202, 2 pls. 
