170 The American Naturalist, [March^ 
ganisms, and all vegetal, excepting those just mentioned 
under the Bacterial division. 
The term microbe may be left where it is now oftenest 
found,— in the newspapers. 
The justification for such a classification as the above, is 
convenience, only. As a matter of fact quantitative ; esti- 
mates of the numbers of micro-organisms in any given sample 
of water, air, ice or snow, are of fundamental importance. At 
present the bacteria are estimated by cultures, and the other 
micro-organisms in ways entirely different.' 
ZOOLOGY. 
The Phalanges of Batrachia Salientia.— Professor 
Howes and Mr. Davies read a paper before the Zoological 
Society of London, Dec. 4, 1888, on the distribution and mor- 
phology of the supenumerary phalanges in the Anurous Batra- 
chians. The authors described for the first time the primary 
mode of development of a supernumerary phalanx. They 
concluded that the same is in the Anura identical with the 
interphalangeal syndesmoses, and that the syndemoses and 
phalanges are derivatives of a common blastema. In its fully 
differentiated condition the structure in question was shown 
to be functional in receiving the direct thrust under the weight 
of the falling body in saltation; all the variations in structure 
being readily intelligible on that view. 
The authors discussed the bearings of the facts upon classi- 
fication and upon the broader question of the morphology of 
supernumerary phalanges in general. They showed that the 
facts of development indicated a probable intercalary origin of 
the latter from the interarticular syndesmoses ; and that the 
numerical increase of the phalanges in the Cetacea may have 
been associated with the loss of ungues, somewhat similiarly to 
the way in which the multiplication of segments of the cartil- 
aginous rays in the paired fins of the Batoidei would appear to 
have been connected with the disappearance of horny fin-rays. 
The authors also showed that the Discoglossidae alone among 
the Anura retained for life the undifferentiated syndemoses, 
Feb., '15, 1889. . 
