No. I.] THE EGG OF UMAX AGRESTIS. 231 



the difficulty of removing the ^g^ from the jelly is greatly in- 

 creased. The jelly can still be removed, however, by allowing 

 the Qgg to stand in water, but this method should be avoided, 

 as it is apt to impair the structure of the Q.gg. Picric acid, 

 chromic acid, and Flemming's solution toughen the liquid con- 

 tents of the capsule so rapidly, that after using them it is often 

 extremely difficult to free the eggs from the capsules without 

 injuring them.^ For this reason these solutions were avoided 

 as killing reagents. 



On account of the small size of the eggs it was found expe- 

 dient to stain them before imbedding in paraffine. The eggs 

 were imbedded in hard paraffine (56 per cent) and cut 3 and 

 4 ii thick. Each 0.%^ gave from 20 to 25 sections. These 

 were mounted serially with Mayer's albumen and water, care 

 being taken to wash off as much of the albumen as possible. 

 The sections were afterwards stained on the slide in Heiden- 

 hain's and Delafield's haematoxylin after iron-alum. 



Various combination stains were also used, chiefly Kor- 

 scheldt's double stain, Lyons blue and borax-carmine, and iron- 

 haematoxylin with orange G. 



Bryn Mawr College, June, 1897. 



^ In place of needles, fine porcupine quills were used in opening the capsules. 

 They proved most efficient implements for the purpose, and have the added advan- 

 tage that they are not acted upon by corrosive sublimate and acids. 



