SOME OBSERVATIONS ON A NEW GREGAEINE. 265 



stiidjiug the structure of the epitnerite, as this organ, in the 

 course of the teasing out, is very easily torn away, leaving 

 decapitated individuals which may be confused Avith true 

 sporonts. By gentle coaxing with a pipette the gregarines 

 can be freed from the bottom of the watch-glass and trans- 

 ferred to a slide for further handlinq-. 



Preparations in toto were made originally under a cover- 

 slip provided with wax feet, and the various reagents di-awn 

 through with blotting-paper. In this way, b}' fixing the 

 gregarines with alcohol and glacial acetic acid (9 : l),a large 

 number of animals may be treated under one cover-slip, Avhich 

 is an obvious advantage. More recently I made some pre- 

 parations by fixing the selected gregarines in a watch-glass 

 with picro-acetic acid (3 : 1) and adding the various fluids by 

 means of a pipette and eventually picking out and mounting 

 the stained gregarines under a low magnification. I consider 

 the former method of treatment the more satisfactory and 

 certainly less laborious. As stains for these preparations I 

 used Grenadier's alcoholic cai-mine solution and Schuberg's 

 modification of Mayer's acid carmine. This latter solution, 

 being acid in reaction and not neutral, has the power of 

 penetrating the cuticle, and in employing it the preparations 

 must be very rapidly washed through with | per cent, 

 solution of HCl to prevent precipitation of the carmine during 

 the further treatment with the alcohols. Leeches destined 

 for sections were fixed either in Gilson's fluid or in the above- 

 mentioned alcohol and acetic mixture. Gilson's fluid should act 

 for two or three hours, and the sublimate constituent be most 

 carefully washed out with iodine-alcohol or a solution of KI 

 in 75 per cent, alcohol. As staining reagents hsematoxylin 

 (Delafield's) and eosin, safranin, and Heidenhain's iron-hasma- 

 toxylin were employed. Owing to the paucity of material, 

 the laborious expedient of applying both methods in succession 

 on the same preparation had to be employed. It was found 

 that htematoxylin and eosiu were satisfactory for the cepha- 

 lonts and sporonts, but gave very incomplete and misleading 

 results with the nuclear changes of the encysted forms, which 



