568 EMBKYOLOGY OF THE LOWER VERTEBRATES CH. 



end of a glass siphon drawn out to a fine point so as to produce the 

 effect of a shower of rain. Within a week or two breeding took place. 



The chief difficulty in the way of cutting sections of Frog's e 

 is due to the presence of the jelly-like envelope. This may be got rid 

 of by prolonged soaking, six months or more, in -5% formalin 

 (Ogushi, 1908), or by fixing in Zenker's fluid and leaving the e- 

 this fluid renewing it after 2 to 3 days and continuing the treatment 



<*. 



e.g.L 

 of. 



E 



op. 



B. 



D. 



KM;. 253. Stages in the development of Phyllomedusa 



/.'. <>( : i-.//, i-xti-rnal gill ; o]>, t>i>erculuin ; of, otocyst. 



for 8 to 14 days or longer, shaking gently so as to remove the envelopes 

 (Kallius, 1908). 



For cutting sections paraffin is commonly used but it should U- 

 supplemented by celloidin e.g. the clove-oil im-tlmd mentioned under 

 Amphioxus. 



In the Urodeles the eggs are commonly laid singly in water and 

 attached to water plants (Triton) or other solid objects such as logs 

 or stones (Proteus, Necturux). In Cryptobranckus and A-tnph'minn 

 they iniiii a MILC, adjacmt envelopes being connected 



together 1)\ a narrow isthmus. 



I 1 1 ili/ai inn is rarely external (Cryptolranchus Smitli, M)12). 

 In the Newtfi th- i. male (ak(?s up a spermatophore into the cloaca. 



