the Midivi/e Toad. 181 



males immediately after they had been fertilized, and placing- 

 them in water drawn from the little pond in which they 

 would have ultimately hatched had they been left to the care 

 of the parent ; but development stopped on the fifth or sixth 

 day, at the period when the embryo produces its external gills. 

 I may add that the egos so treated dii] not show the extra- 

 ordinary " Aufquellen der Gallerthiille, genau wie dies bei 

 anderen Anuren-Eiern der Fall ist " (1, p. 74). 



I fully expected some reason would be forthcoming on the 

 part of Kammerer to explain the failure of my experiment, 

 and so it was ; but I should never have thought him capable 

 of making a new statement so contrary to the plain wording 

 of the sentence quoted above, which is to the effect that, alter 

 lying thirteen to fifteen days in water 3 cm. deep, no 

 manipulations being mentioned, the larvge (all or most of 

 them, as anyone would understand) swarmed out (" schwarm- 

 ten aus ") of the egg-capsules. I was therefore, I think, 

 fully justified in saying"^ "II en serait autrement des Alytes 

 de Westphalie, appartenant pourtant ^ la m^me espece, puis- 

 que Kammerer, operant avecceux-ci, ne semble avoir aucune 

 difficult e k contrarier ainsi I'ordre de la nature." 



Now this is what Kammerer, replying to my criticism, 

 tells us (5, p. 260) really happened on that occasion : — 



" Junge ^/yiC'i-Eier befinden sich, unter Wasser liegend, 

 an sich schon nicht unter ' natiirlichen'' Bedingungen, und, 

 um diese zu kompensiren bedarf es ebenso 'unnatiirlicher ■* 



Gegenbedingungen in peinlicher Sterilhaltung des 



Laiches : in ausgekochtem, dann kiinstlich durchliiftetem 

 Wasser. Trotzdem dringen nocli Schimmelkeime ein, und 

 jedes befallene Ei muss sorgtaltig entfernt werden. Bei 

 Einhaltung dieser Vorsichtsmassregeln mussten immerhin 

 zahlreichere Eiballen abgestorben in den Kiibel wandern, als 

 Herr Boulenger wohl sie zu seinen Versuchen verwendet hat, 

 bis ich endlich an einigen wenigen Eier einiger weiiio-er 

 Eierballen mit der submersen Eutwicklung Gliick hatte.'' 



Why, it may be asked, was all this not mentioned, at first, 

 instead of letting the reader believe that the embryos under- 

 went the whole of their development without any intervention 

 on the part of the experimentator. 



From this sample of the levity with which Kammerer 

 relates iiis experiments, is it surprising if some of his state- 

 ments should be challenged by those who, like myself, do not 

 place implicit confidence in them? 



* BuU. Ac. Belg. 1912, p. 579. 



