36 FROGS. 



tion, due to inequalities of growth. This supposition is borne out 

 by observation. In none of the species under consideration is there 

 such a range of size at transformation as in the bullfrog, which at this 

 period varies from 1.7 to 2.35 inches in length, with an average of 2.1 

 inches. (See fig. 2 and Pis. XXI, fig. 1, and XXII, fig. 1.) 



Some of the southern bullfrog tadpoles may transform in the very 

 last of May, and the minimum transformation size recorded is If 

 inches. (See fig. 2.) 



Possible Species. — The toad tadpole is among the first of the 

 season to transform. When transformation is taking place, the 

 shores of some ponds are black with myriads of little toads, their 

 numbers being particularly noticeable when they leave the shores 

 and cross near-by roads and streets. Transformation begins the 

 last of June and may continue into August and rarely into Septem- 

 ber. The author's earliest record of transformation is June 8. The 

 average date is June 21. The size at transformation is small, rang- 

 ing from 0.3 to 0.5 inch in length, the average being 0.4 inch. (See 

 fig. 2 and Pis. XXI, fi^. 8, and XXII, fig. 10.) 



The wood frog usually begins transformation about July 1. The 

 transformation may begin as early as June 8 or extend to August 1, 

 and the transformation size varies from 0.5 to 0.85 of an inch, the 

 average being 0.6 of an inch. (See fig. 2 and Pis. XXI, fig. 6, and 

 XXII,fig. 8.) 



The hermit spadefoot toad transforms from June to August and 

 ranges in size from 0.3 to 0.5 of an inch at the time of transformation. 

 (See fig. 2 and PI. XXII, fig. 11.) 



Undesirable Species. — The undesirable forms, when full grown, 

 are small and the young transformed frogs are also small of size, 

 none of them ranging over 0.8 of an inch and most of them having 

 an average size of 0.3 to 0.7 of an inch. 



The narrow-mouthed toad tadpole may transform from the middle 

 of June to September or October. The average size at transforma- 

 tion is 0.5 of an inch. (See fig. 2 and PL XXII, fig. 9.) The tree 

 toad transforms largely during the last of July and the first of August. 

 The size at transformation varies from 0.5 to 0.8 of an inch, the 

 average being 0.6 of an inch. (See fig. 2 and Pis. XXI, fig. 5, and 

 XXIIi fig. 15.) The peeper tadpole usually begins to transform as 

 early as July 1, although the average date is July 6. The range of 

 transformation is from June 12 to August l,and the range of size is 

 0.35 to 0.55 of an inch, the average being 0.4 of an inch. (See fig. 

 2 and Pis. XXI, fig. 7, and XXII, fig. 16.) The swamp cricket frog 

 usually has finished transformation by July 1 and may transform 

 as early as June 1. At transformation the frog is 0.3 to 0.5 of an 

 inch in length. (See fig 2 and PI. XXII, fig. 13.) The cricket frog 

 transforms from June 1 to July if the eggs be laid early, or in August 

 if ttie eggs be laid in June. At transformation it averages a OTeater 

 length than the swamp cricket frog, being 0.5 of an inch in length. 

 (See fig. 2 and PI. XXII, fig. 14.) 



RATE OF GROWTH. 



The rate of growth from transformation to the full-grown adult 

 condition (fig. 2) is very important. If a frog requires a long period 

 to reach adult estate, then such a factor is one item which militates 



