1897,] Zoology. 987 
their eggs. The ova are pale yellow, ellipsoidal in shape, measuring 
2.5x3 mm.—Nature, August 26, 1897. 
Zoological Articles in Recent Journals.—In Vol. 105 of the 
Sitzungsberichte of the Vienna Academy, Dr. Franz Werner writes 
upon the Sealing of the Reproduced Tail in Lizards; Dr. F. Stein- 
dacher upon some Zoological Results of the Expedition of the “ Pola” 
to the northern part of the Red Sea;, Dr. P. Knold upon the Blood 
Corpuscles of Vertebrates; and Dr. H. Albrecht upon the Comparative 
Anatomy of the Mammalian Larynx. 
PSYCHOLOGY.’ 
Odor-mixture.—The relation of elementary sensations to the 
sensation of their compound has given rise to much theoretical discus- 
sion. In the senses of sight and hearing it has also been the subject of 
considerable experimental work. The laws of color-mixture have long 
since been formulated, and the sequence of the color series, like that of 
the tone series, is well known. In the domain of smell, owing to prac- 
tical difficulties that attend the investigation, little progress has been 
made. Certain odors stand marked as qualitatively distinet, but their 
relations to one another and the arrangement of their “shades ” into a 
single graduated series has never yet been satisfactorily demonstrated. 
On the other hand, it has been shown that odor-mixtures (of many 
odors, at least) give rise to new and qualitatively simple odors, thus 
resembling the color-mixtures rather than the accords of tone combina- 
tions. Zwaardemaker, in a recent work, gives a series of nine distinct 
classes of odors, into one or other of which he thinks any particular 
odor can be placed. He resolves compound odors into elements belong- 
ing to two or more of these classes. When the organ of smell is fatigued 
for one class of odors, the remaining elements in the compound are 
sensed, and if the compound consists of but two elements they may 
readily be distinguished by this means. Both this author and Aron- 
sohn, an earlier writer, speak of certain odors which do not combine to 
form a mixture, but when placed together give rise to a blended sensa- 
tion, each element of which may be sensed separatively at will, In 
some compounds, again, one element predominates so strongly that the 
other is wholly indistinguishable. 
1 Edited by Howard C. Warren, Princeton University, Princeton, N, J. 
