Rana septentrionalis 417 



There is another point of view expressed in H. H. T. Jackson's "The 

 Land Vertebrates of Eidgeway Bog, Wisconsin: Their Ecological Succession 

 and Source of Ingression. (Bull. Wise. Nat. Hist. Soc. Vol. 12, Nos. i and 2, 

 June 1914, pp. 17, 18). "The northern frog, Ra7ia septentrionalis, has been 

 considered by some herpetologists to be a subspecies of Rana clamitans; 

 specimens of the two forms are often morphologically very similar, but their 

 habits and behavior are so widely at variance that it seems improbable they 

 interbreed. For example, Rana septentrionalis is relatively, a sluggish frog; 

 during the summer months it is found along the edge of lakes and streams, 

 usually with the body partly submerged in the water, occasionally on land 

 at the water's edge; when alarmed it utters no sound, makes a feeble leap 

 of two or three feet into the water, settles to the bottom and hides in the mud 

 or under some object where it is easily captured in the hand. Contrast with 

 the behavior of this frog that of Rana clamitans] the latter is an active frog; 

 during the summer months it is almost invariably found out of the water on 

 a gently sloping bank; when alarmed it utters a loud startling croak, makes 

 a vigorous leap of five or eight feet into the water, swims some distance 

 under water before hiding, where it remains alert and difficult to capture. 

 There remains, of course, the alternative to explain this as "one species 

 having different mores" (Shelford, 1912a, p. 92), but one can hardly accept 

 this view in the present case." 



Such discussions are unsatisfactory. It depends on what characters one 

 knows best, what he is most interested in, or what he accidentally discovers 

 that he uses as his criteria or canes on which he leans. What follows may 

 be of no consequence : 



1 . Little evidence can link it with Rana sylvatica or R. cantabrigensis. 

 Sometimes the adults are almost free of spots like Rana sylvatica, 

 R. cantabrigensis, or some of the Northwestern species. Its eggs are 

 with two jelly envelopes and the above species have the second 

 indefinite. The egg mass is submerged as in R. sylvatica, or R. ca7ita- 

 brigensis and about of the same size. The woodfrog and northern 

 woodfrog choose woodland pools, etc.; R. septetitrionalis, peaty lakes, 

 waterlily ponds. The tadpoles are wholly unlike the woodfrog, one 

 transforms the year laid and the other after wintering over at least 

 one season. The two have deep tail crests far forward in body and 

 with labial tooth rows more numerous, while R. septentrionalis has 

 the elongate large narrower tail crests of a Rana clamitans type and 

 tooth rows 23. The two transform at a small size; R. septentrionalis 

 transforms at a variable but usually large size. There is little in 

 common with the woodfrogs. 



2 . Rana pahistris. 



The pickerel frog (Rana palustris) is one of our most poisonous 

 frogs with a decided odor. So also Rana septentrionalis is the "mink" 

 frog. Therein they might be associated if secretions be the criterion. 

 Each lays submerged egg masses, each has eggs quite similar in size. 



