152 Review of the Progress of North American (February, 
As many as 1380 eggs are contained in a single mass. The time 
in which the eggs develop varies greatly according to temperature. 
The metamorphosis of the tadpoles observed occupied from April 
12 to June th, when the tail had wholly disappeared, and tadpoles 
which on May 31st measured 58™" in length were reduced to 
young frogs 18" long. The external gills became fully developed 
two days after hatching, and in four days more were entirely re- 
sorbed, leaving an opening through which the action of the inter- 
nal gills could be seen. The legs budded on May 6th, and by 
May 20 the feet and toes were well defined. 
In the Canadian Naturalist (Vol. 9, p. 160), Mr. H. Mont- 
gomery observes that examples of Menobranchus kept in an 
aquarium plentifully stocked with mollusks fed entirely upon fishes. 
Mr. W. Frear, ina note to the AMERICAN NATURALIST, gives a 
curious instance of the vitality of this batrachian. An individual 
that had lain exposed to the summer sun for forty-eight hours, 
and had been completely covered with alcohol for twenty hours 
gave undoubted signs of vitality, by opening its mouth and sway- 
ing its tail, when placed on the dissecting table. 
Mr. J. S. Kingsley (Proc. Bost. Soc., 1881) notices a case of 
polymely, or the development of an additional limb, in an exam- 
ple of Rana halecina. The supernumary limb, is in origin a 
structure a limb of the left side, but occupies nearly the position 0 
a tail. The myology of the proximal part of this extra leg !$ 
less perfect than that of the distal, but the most singular abnor 
mality is the formation of an acetabulum for the odd limb at th 
symphyis of the pubes. 
Wm. E. Carlin (Proc. U. S. Nat. Mus. 1881) states that large 
numbers of the Stredon lichenoides of Como Lake change every 
season to the Amblystoma state, but that the change takes plae 
much more slowly in the alkaline waters of the lake than in fresh 
water. : 
S. F. Clarke (Johns Hopkins University, Studies from the Bio 
logical Laboratory) gives the result of observations upon me 5 
velopment of Amélystoma punctatum, The eggs are deposited 1 
masses of from two to three hundred, each covered with 4 pi 
cious gelatinous coating, at first thin, but rapidly becoming thi 
by absorption of water. Thus each egg consists of two st 
nous shells, separated by a space filled with clear fluid, and “ 
well protected from voracious fishes. In the act of depos! 
