34 T. IJIMA : HEXACTINELLIDA. I. 



For killing and fixing the soft tissues, trials were made with 

 a large number of reagents, such as absolute alcohol, concentrated 

 solutions of corrosive sublimate (used cold or hot and with or 

 without the addition of a little glacial acetic acid), Pere.xyi's 

 fluid, Flemming's weak solution, Hekmaxn's fluid, V2o-Vio9^ osmic 

 acid, &c. Of all these, corrosive sublimate dissolved in sea- 

 water gave me fairly constantly the best results. All the rest 

 were rather uncertain as to the outcome. I have also tried, for 

 the sake of comparing the results, such slow Avorking reagents 

 as chromic acid and picrosulphuric acid from which no good 

 outcome could be anticipated, and have even sectionized samples 

 which were purposely macerated by leaving them in water. 



One of the advantages of using corrosive sublimate dissolved 

 in sea-water is the simplicity of the method, which is an item 

 of great importance when one has to work in a small open boat 

 as I have had to do. I used to prepare the solution on the way 

 to the collecting ground by simply adding the sublimate to a 

 small bottle of sea-water in a quantity somewhat greater than 

 could be dissolved. The bottle was shaken now and then during 

 the few hours I had still to wait. Pieces of the sponge, each 

 in size not more than lö mm, square, were thrown into the 

 fluid and left there for about half an hour, sometimes longer. 

 They were then washed in distilled water, using a pair of bamboo 

 chopsticks for picking them up. During the return journey, 

 they usually remained in a plent}^ of distilled water in a large 

 bottle, which was once in a while carefully moved so as to set 

 the objects swimming. Reaching shore, the objects were put into 

 70"/o alcoliol, wliich was changed in an hour or so. After at 

 least 24 hours, they were transferred into dOfo alcohol, to be 

 replaced with absolute alcohol in another da}' or two. In 



