Rana septentrionalis . 409 



Period. Previous to 1923 we knew nothing positive of the eggs except 

 Garnier's records. Several of my friends volunteered to help in the search 

 that summer, and at least three of us independently found the species breed- 

 ing in different places. Mr. S. C. Bishop had kindly invited me to join him 

 at Hart Lake July 13 and 14. I could not make the proper plans and he 

 went to Hart Lake and Mrs. Wright and I to the Fulton Chain of lakes, 

 Adirondacks. We found only two masses at Onekio, N. Y., the species just 

 beginning while Mr. Bishop reported the species well launched in Hart Lake, 

 Adirondack Lodge, near North Elba and Mt. Marcy. On July 16 I saw a 

 letter from Mr. S. E. R. Simpson who at Dorset (Otter Lake), Ontario, 

 reported on July 8 that he believed he had found the mink frog eggs. These 

 three independent discoveries July 8-14 would seem to indicate the first 

 of July as a part of the crestal period of ovulation. Mr. Garnier's records 

 June 24 and July 30, 1883, are yet the extreme dates of ovulation. We, 

 therefore, have from June 24 to July 30, possibly August 16 as the egg period 

 with the bulk of eggs laid in July. Most of the U. S. National Museum 

 accessions are for the month of July when this inconspicuous species is 

 croaking and most in evidence. U. S. National Museum No. 36097 is a 

 female 67 mm. and ripe. It was taken July 9, 1903, at Cross Lake, Aristook 

 Co., Me., by Mr, W. C. Kendall. On the same day of the month, July 9, 

 1900, G. S. Miller Jr., secured a ripe female 61 mm. (U.S.N.M. No. 28355) 

 at Peterboro, N. Y. These help to reinforce the impression that July is its 

 principal breeding month. 



Egg-laying process. Doubtless the bulk of egg laying is at night. The 

 males await the coming of the females. When they approach the males rush 

 for them and soon they amplexate. It would seem they soon sink to the 

 bottom. As with other Ranas which lay plinths the laying after it has begun 

 probably lasts from a few to 15 or 20 minutes. As yet no one has seen the 

 actual process. 



EGGS 



We have already seen that the mass is a plinth with its greatest diameter 

 rarely as large as 6 inches, although 3-5 inches are the more usual dimensions. 

 In breeding habits the species reminds me of Rana virgatipes, each with 

 plinths except that R. septentrionalis has an inner envelope around each egg, 

 or of R. palustris which has a globular mass of eggs more brown and yellow. 

 R. palustris has the more brownish and more yellowish eggs; R. virgatipes 

 is next and R. septentrionalis eggs have a slight brownish and yellowish cast 

 at times. In the two masses we found at Onekio the fresher bunch had almost 

 black above and cartridge buff below. Later the lower color was almost 

 white. The older bunch had the eggs seafoam yellow or light chalcedony 

 yellow below and a dark brown above. Mr. Bishop held that "the upper 

 half in freshly laid eggs is black; the lower half creamy white, division of 

 color being about equal." Mr. S. E. R. Simpson speaks of them as a brown 

 mass — whether it is from the sediment in its general effect on the upper poles 

 I do not know. 



