444 THE AMERICAN NATURALIST. [Vor. XXXIV. 
extensive and complicated growth processes in which no simple 
plane of division can be recognized. 
An interesting prorhynchid turbellarian from deep wells in New 
Zealand has been described by Haswell (Quart. Journ. Micr. Sci., 
Vol. XL, pp. 631-645, Pl. XLVIII). It is most closely related to 
the Prorhynchida and not to the Alloioccela, as at first believed. 
The complicated pharynx, the lateral vitello-germarium, and the 
unpaired lateral testis are among the important peculiar structural 
features of this form which the author includes provisionally in the 
genus Prorhynchus. 
In an extended study of the morphology and physiology of EugZena 
gracilis, Zumstein (Inaugural-Dissert, Basel, 1899) shows that this 
species does not manifest anything of an animal method of life. Its 
nutrition may be purely holophytic, purely saprophytic, or both com- 
bined, but thrives best under the latter. The colorless variety of the 
species may be transformed into the green, or vice versa, with corre- 
sponding change in manner of nutrition. 
The frequency of trematodes has been studied by Hausmann 
(Centralbl. f. Bakt. u. Par., I. Abth., Bd. XXVI, pp. 447-453) in 
birds from Baden and the vicinity of Basel. The percentage of 
infection found was, Grallatores 29, Raptatores 26, Natatores 25, 
Corvidz 24, which is from three to six times as de as numbers 
previously listed from birds. 
Number IX of the third volume of the American Journal of Physi- 
ology contains the following articles: *On the Reactions of Chilo- 
monas to Organic Acids,” by H. S. Jennings; “Notes on the 
Individual Psychophysiology of the Crayfish,” by G. V. N. Dearborn ; 
* On the Artificial Production of Normal Larva from the Unfertilized 
Egg of the Sea Urchin," by J. Loeb ; and **On the Maximum Pro- 
duction of Hippuric Acid in Rabbits," by W. H. Parker and G. 
Lusk. 
In a reply (Archiv f. die ges. Physiologie, Bd. LXXIX, 1900) to a 
criticism of his paper on the psychic qualities of ants and bees, Albert 
Bethe tells us that the chief error in his work is that he did not 
distinguish clearly enough between objective expression and sub- 
jective “ Empfindung” in our own psychological processes. He 
says that he agrees with Uexküll that the question concerning the 
Psyche of animals does not belong to the realm of exact science, 
and he declares that he is ever willing to discuss the question 
