ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 149 



sharp canula, with fine injecting mass, then the canula is inserted in 

 the generative cloaca or opening of the vagina, thus cutting the excretory 

 canal. If the canula is inserted the proper distance, the entire caudal 

 portion of the water-vascular or excretory system can be injected. The 

 injecting mass does not flow towards the head on account of the opposing 

 valves. For the museum nothing further is done, except to wash the 

 worm with water and suspend it in a bottle of 75 per cent, glycerin, to 

 which has been added a few drops of acetic acid. The worm will soon 

 clear up and show all the structures with the greatest clearness. 



For microscopical preparations, one and a half or two segments, 

 after treatment as above, are mounted on a slide in a cell of glycerin 

 jelly. For the most satisfactory microscopical preparations, the ovaries 

 and uteri, as well as the excretory system, should be injected. This is 

 accomplished by first injecting the excretory system with one colour as 

 described above, and then by employing another colour and forcing the 

 canula further into the worm than when injecting the excretory system. 

 Segments so injected may be preserved in glycerin jelly, or after gradual 

 dehydration, in Canada balsam. Uninfected segments may be hardened 

 in Muller's or Ehrlich's fluid, and then in alcohol, and made into serial 

 sections to show the finer structural details. 



Methods of studying Sphyranura.* — Prof. E. Kamsay Wright and 

 Mr. A. B. Macallum found that specimens of Sphyranura were rarely 

 too large to prevent complete study in the fresh condition. The 

 most completely satisfactory reagent was Flemming's chrom-osmic- 

 acetic mixture: an example being placed in water sufficient to cover 

 it, a drop of the reagent was placed beside that in which the worm lies 

 and the two were allowed to mingle, with the result that in five or ten 

 seconds death, but not complete fixation, occurs. The greater part of 

 the fluid being drained away the worm was gently straightened out 

 with a needle, and a second drop of the reagent added for two or three 

 minutes. The specimen must now be transferred to a larger quantity 

 of the reagent, in which it must remain for thirty minutes, and it must 

 then be passed through various strengths of alcohol from 30 to 90 per 

 cent. Lang's Planarian fluid, and solutions containing picric acid cause 

 shrinkage. Delage's osmic carmine has no advantage over Flemming's 

 fluid. The process of imbedding used was the chloroform-paraffin 

 method, the substitution of chloroform for turpentine having been found 

 to obviate shrinkage of some of the delicate cells. Alum-cochineal was 

 most satisfactory for staining specimens in toto. 



Histology of Echinoderms-t — In making his observations on the 

 minute anatomy of Echinoderms (see supra, p. 53), Dr. 0. Hamann 

 found that Flemming's chrom-osmic-acetic acid mixture was useful with 

 the organs attached to the body-wall. With young and small animals 

 chromic acid was used. Urchins preserved in strong alcohol were 

 decalcified by placing small pieces in a • 3 per cent, solution for a day, 

 and washing them for twelve hours ; these preparations took well the 

 hseniatoxylin-stain. The pedicellarias were either decalcified and cut, 

 or were cut after treatment with Flemming's solution. The stainin" 

 reagents used were, generally, carmine solutions ; in the examination of 

 glandular organs the anilin colours were useful. After treatment with 



* Journ. of Morphology, i. (1887) pp. 4-6. 



t Jenaische Zcitschr. f. Naturwiss., xxi. (1887) pp. 88-9. 



