General Discussion 29 



Scaphiopus holbrookii cf X Hyla gratiosa 9 



Bufo terrestris cf X Rana sphenocephala cf 



Bufo terrestris cf X Rana sphenocephala 9 



Bufo terrestris cf X Hyla gratiosa cf 



(Rana septentrionalis cf X Rana clamitans 9 ) 



When ovulating is taking place in the same place for several species, 

 embraces might occur. For example, a Bufo terrestris male might leap at 

 Hyla femoralis, Hyla cinerea, Hyla gratiosa, Scaphiopus holbrookii or any 

 other if it approaches its size. 



Some workers on the basis of few observations may think the males can 

 distinguish sexes but countless cases of males mating have been observed. 

 We did not record all we saw, but have in our notes the following species 

 where males amplexated : 



Bufo quericicus Hyla squirella 



Bufo terrestris Hyla versicolor 



Acris gryllus Pseudacris ocularis 



Hyla femoralis Rana sphenocephala 



Or to make the case more pronounced males sometimes mate in a tier of 

 three : one female below with a male atop the male mating with her. We recall 

 such a case in Pseudacris ocularis, Bufo quercicus and Scaphiopus holbrookii. 



Abnormal embraces with forms other than frogs were not sought or 

 observed. 



DEPARTURES FROM CUSTOMARY AMPLEXATION AND 

 THEIR SIGNIFICANCE 



(PL IV, Figs. 5, 6, 8) 



In 1914 we remarked the emphasis laid by European workers on form of 

 embrace or amplexation in differentiating or diagnosing certain families or 

 genera. In Dr. Gill's comments on Boulenger's Tailless Batrachia he notes 

 that differences may in part be due to differences in size between males and 

 females and must vary. 



Since the Ithaca paper we have seen the amplexation of almost every 

 species of the southeastern United States. In general with eastern Salientia 

 we can say that every species of Rana embraces pectoral-like; that every 

 Hylid (Acris, Pseudacris, Hyla), each Bufo (B. americanus, B. fowleri, B. 

 terrestris, B. quercicus), and the narrow-mouthed toad {Gastrophryne carolinen- 

 sis) are axillary or supra-axillary in fashion while the spade-foot is inguinal. 

 But every one of these may at times be varied from the normal. 



Relative size, beginning, crest or waning of impulse or exhaustion of male 

 or presence of other males may dictate the form of amplexation. 



In most of the species of Okefinokee when enough pairs were at hand 

 variations occurred. 



Sometimes a male will seize a female in pre-axillary form (Gastrophryne) . 

 Or a small male may apparently have to be supra-axillary or pre-axillary in 

 front of forearms over the tympanum (Bufo terrestris). Or a male if it has 



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