A CONTRIBUTION TO THE DEVELOPMENT OF 



PARYPHA CROCEA. 1 



CARRIE M. ALLEN. 



MY work has been carried on at the Zoological Laboratory of 

 Syracuse University under the direction of Dr. C. W. Hargitt, 

 to whom it is a pleasure to express my obligations for his kind 

 suggestions and supervision throughout its progress, and for 

 the pains which he has taken in furnishing me with the best 

 of appliances and material. The material upon which the 

 investigations have been made was collected by Dr. Hargitt at 

 Woods Holl, Mass., during the summer of 1898. Through 

 his kindness I had at my disposal an almost limitless supply 

 killed and preserved by a number of methods. Picro-sulphuric 

 acid and Perenyi's fluid both gave excellent results, but forma- 

 lin proved unsatisfactory for histological work. 



In most of my study I used preparations stained in toto in 

 borax-carmine. The specimens were left in alcoholic borax- 

 carmine for twelve hours, after which the stain was extracted 

 by acid alcohol for from fifteen minutes to half an hour. In 

 dehydrating they were left in each of the various grades of 

 alcohol for thirty minutes, after which they were cleared either 

 in cedar oil or chloroform. Both clearing agents gave good 

 results, but the latter was preferable because of its rapid 

 action. 



In staining on the slide, iron-haematoxylin and double stain 

 of eosin and haematoxylin both proved satisfactory. 



In using the iron-haematoxylin the sections were fixed to the 

 slide, carried down through the alcohols to 50 per cent, and 

 placed in a 2 per cent solution of ammonio-ferric-alum for from 

 thirty minutes to three hours. They were then washed in 

 running water for twenty minutes, stained in 0.5 per cent 

 aqueous solution of haematoxylin for from one-half hour to 



1 Contributions from the Zoological Laboratory, Syracuse University. 



291 



