320 ENTOMOLOGY. 



55 C. The embedding mass is rapidly cooled. The sections are 

 stuck on with a thin layer of Mayer's fluid. The author states that 

 fresh albumen mass stains less easily than the older. The stains 

 used were Grenadier's borax-carmine, Weigert and Ranvier's picro- 

 carmine, and Flemming's hsematoxyliu. The author recommends 

 double staining with picrocarmiue and haernatoxylin ; weak staining 

 first with picrocarmiue and afterwards with the logwood. The dye 

 is then extracted with acidulated alcohol until a red hue appears; 

 the sections are then transferred to arnmoniacal alcohol until the 

 blue color reappears. In order to obtain various shades of color the 

 author advises to stain about f of the sections (sic) with picrocarmiue, 

 and then to draw out the slides from the fluid so that the upper part 

 is more deeply stained than the lower. The slide is then turned 

 round and the process reversed with haematoxylin. Afterwards 

 absolute alcohol, bergamot oil, xylol balsam, Flemming's chrom- 

 osmium-acetic acid, and safranin staining give good results. Fix- 

 ation with 3 per cent nitric acid produced vacuoles in the yolk, and 

 was, therefore, of but little use. 



Dr. H. Henking,* in his investigations into the development of 

 the Phalangida, adopted various methods of preparing the ova ; the 

 animals were sometimes killed with boiling water, and left in it for 

 some time for the albumen to coagulate ; they were then hardened 

 in successive strengths of alcohol up to 80 per cent. The ova were 

 never placed direct in alcohol, in consequence of the shrinking 

 caused by such a process. Other specimens were killed with ether, 

 the back laid open, and the animals placed in Flernmiug's chrora- 

 osmic-acetic acid or in Kleineuberg's picrosulphuric acid for some 

 hours before removal to alcohol. Eggs that had been deposited 

 were treated with hot water, and with Flemmiug's fluid, as well as 

 with hot and cold chromic acid, picrosulphuric acid, etc. The best 

 staining reagents were found to be Grenadier's borax-carmine, 

 Hamauu's neutral acetic acid carmine, and eosin-hoematoxylin. 

 Before embedding, the eggs on being taken from absolute alcohol 

 were placed in a mixture of bergamot oil and absolute alcohol, then 

 in pure bergamot oil, and then in a warmed solution of parafflne in 

 bergamot oil, and finally in quite pure paraffine. By the aid of 

 Speugel's microtome sections from ^ to -^5 mm. thick were pre- 

 pared. 



Dr. F. Blochmann fixes the ovaries of ants and wasps with picric 

 acid or sublimate, staining them on tt-e slide with picrocarmine or 

 borax-carmine. For examining the elements of the yolk, double- 



* Zeitschrift fur. wiss. Zool., xlv. (1887) pp. 88-90; Journ. Roy. 

 Micr. Soc., August, 1887. 



