362 BOTANICAL GAZETTE [MAY 
but if scions of some susceptible species are grafted on the former these become 
infected, showing that the virus can pass unchanged through the intermediate 
piece of A. arboreum. These experiments seem to prove the existence in the 
plant of a substance which in its behavior is analogous to the supposed shoot- 
forming substance of SAcHs, or the growth enzymes of BEyERINCK.—H. Has- 
SELBRING 
Anatomy as a test of species—ALrrepD SaRrToN’® has made an elaborate 
experimental study of the anatomy of related plants, to test the constancy of 
anatomical characters under varying conditions of climate and of soil. . 
work was done at the Botanical Laboratory of the Sorbonne and at the Labora- 
tory of Plant Biology at Fontainebleau. He calls attention to the fact that there 
are two kinds of species recognized in taxonomic writings: one he calls the “ Lin- 
naean species,’’ which often bring together under a single name a large number 
of different forms; the other he calls the “ Jordanian species,”’ which often consist 
of dismembered Linnaean species. These two kinds stand side by side as of 
equal rank, all of them based upon varying judgments as to the value of exter- 
nal morphological characters. 
ARTON Set out to discover whether real species could be detected by their ana- 
tomical characters. He reasons that nearly allied species whose anatomical 
differences may be exchanged under experiment are not separate species, however 
unlike they may appear externally; and that those whose anatomical differences. 
are constant under experiment are true species, however similar they may appear 
externally. To test this dictum involved a large amount of laborious experi- 
mentation and anatomical investigation. The result was to pronounce some 
Jordanian species good and others not; and the Linnaean species shared the same 
fate. This anatomical method, therefore, furnishes no basis for judgment between 
the two types of species; and if it is used, it seems to the reviewer that it will 
result in readjusting specific lines without settling anything. 
The fundamental weakness in this whole point of view is the idea that there 
can be any rigid test for that elusive conception known as a “species” which will 
carry it beyond the reach of fallible and hence diverse human judgment. It. 
is of great interest to know what anatomical characters will vary under given 
conditions, and herein lies the chief value of this investigation; but even here 
the conditions are not analyzed so as to be convincing. To regard these char- 
acters as outweighing all others is to stir afresh the seething mess of taxonomy. 
What we need is not more ‘‘specifics’’ but more hygiene.—J. M. C 
Transpiration of evergreens.—Puc.isi"’ has published a paper on the trans- 
piration of seven species of Chinese and Japanese evergreen trees and shrubs. 
16 SARTON, ALFRED, Recherches expérimentales sur l’anatomie des plantes 
affines. Ann. Sci. Nat. Bot. IX. 2:1-115. pls. I-4. 1905. 
*7PuGLIsI, M., Sulla transpirazione di alcune piante a foglie sempreverdi. Annali 
di Botanica 2:435-468. pi. 2. 1905. 
