5o8 



ON INCREASE IN SIZE 



[PT. Ill 



As Ephrussi says, the correspondence can hardly be a mere coin- 

 cidence, and in any case the fact that change of temperature has 

 almost no effect on process C must be significant. 



We do not know whether the effect of increased temperature is 

 greater on the mitotic or inter-mitotic period. Bucciante main- 

 tained chick embryo explants at 31° and at 41° and counted no more 

 mitoses during a given amount 

 of growth in the latter than in ^ 

 the former, so he concluded that '~ 

 the effect was the same. 



Loeb & Wasteneys found 2-3 

 for the embryonic growth of 

 Arbacia and Bohr 2-9 for that of 

 the snake Coluber natrix. Warburg 

 gave 2-5 for the respiratory in- 

 crease of Arbacia eggs. Herzog, 

 working on the figures of Dan- 

 nevig for the hatching time of the 

 plaice egg {Pleuronectes platessa), 

 got a Q^io of 2-5, on those of Earll 

 for the cod egg [Gadus morrhua) 

 3-4 and 2-3, and on those of 

 Ainsworth and Metzger for two 

 different kinds of trout egg 3-4 

 and 5-3. Later, Bachrach & 

 Cardot obtained a value of 3-2 

 for the embryonic growth of the 

 slug Agriolimax agrestis between 

 6 and 23°, and one of 3-06 for that of the water snail Limnaea stagnalis 

 between 1 1 and 32°. For Ascaris megalocephala Zavadovski got a Q^^q of 

 2-8, but it was markedly higher at low temperatures than at higher 

 ones. Then later, Zavadovski & Sidorov gave Q^io (18-28°) 3-12 for 

 Toxascaris limbata, 3-12 for Ascaris megalocephala and 3-23 for Ascaris 

 suilla, but 1-45, 1-46 and 0-73 respectively between 28 and 38°. Brown 

 has also published a Q^^q for Ascaris, Berrill for Lophius americanus, 

 Harukawa for the oriental peach-moth, Kawajiri for Salmo irideus, 

 Nakai for Plecoglossus altivelis, Kojiyama for Pagrosoma major. 



But the older phase of the work on the effect of temperature on 

 embryonic growth could not lead to any definite conclusions about 



