No. 40o1.] REVIEWS OF RECENT LITERATURE. 445 
whether or no ants and bees have the power to purposefully modify 
their acts (Modifications vermögen besitzen), and whether a * Rema- 
nenz” of a stimulus is possible in them. But whether they possess 
a psychical quality or not, he will not discuss, since the objective 
expressions of animals and the causes of these are all that legiti- 
mately belong to biological research. W. E. R. 
A supplementary part has been issued to Vol. XV of the Journal 
of Morphology and contains the following articles: * On Protoplasmic 
Structure in the Eggs of Echinoderms and some other Animals," by 
E. B. Wilson; * Studies upon the Early History of the Ascidian Egg," 
by H. E. Crampton ; * The Spermatogenesis of Amphiuma,” by J. H. 
McGregor; “ The Calciferous Glands of the Earthworm, with Appen- 
dix on the Circulation," by N. R. Harrington; “ The Changes in the 
Structure of the Pancreas Cell," by A. Mathews; and * The Sper- 
matogenesis of Anasa tristis," by F. C. Paulmier. The supplement 
has a paging of its own, but is unaccompanied by a table of:contents 
or title page. 
BOTANY. 
Phenological Observations in Canada.— Mr. A. H. Mackay! 
gives an account of some interesting phenological observations made 
in Canada during the seven years 1892 to 1898. This was one of 
the lines of work undertaken by the Botanical Club of Canada, and 
from nine to nineteen reports were received each year, giving more 
or less completely the time of the appearance of leaves, flowers, 
and fruits and the migration of birds. The author calls attention 
to the many difficulties of obtaining complete and accurate records ; 
for example, the more rare species may easily escape notice until 
they have been in flower for some time. Again, some individual 
plants are earlier than others in the same locality, and in the same 
individuals certain branches are earlier than others, hence the records 
were made to include “first appearance " and ** becoming common.” 
A phenological date is defined as *a sort of mathematical function 
of variables," which is influenced by variations in temperature, of 
atmospheric pressure, sunshine, precipitation, together with the local 
constants, latitude, elevation, slope, proximity of bodies of water, 
and character of soil. The rapidity with which a season advances, 
1 Canadian Record of Science, vol. viii, pp. 71-84, 1900. 
