! 18 SUMMARY OF CURRENT RESEARCHES RELATING TO 



obtaining the polyps in an extended condition ; they were put directly 

 from the water into the solution, when tho separate individuals 

 generally contracted. But in a short time they gradually extended 

 themselves again, and soon became insensible. In some cases chloral 

 hydrate was added by drops. They were then put into a saturated 

 solution of sublimate; after being for ten minutes in this, they were 

 washed in water for half an-hour and then presorved in alcohol. The 

 best preparations were thus obtained, and this method was distinctly 

 preferable to killing them directly by alcohol or with osmic acid. 

 Borax-carmine (with a small quantity of acetic acid) gave the best 

 staining results, the preparations being subsequently treated with 

 70 per cent, alcohol and a few drops of hydrochloric acid. In the in- 

 vestigation of the living animals, F. E. Schulze's horizontal Microscope 

 was found to be of great service. 



Methods of studying Development of Eye of Crangon.* — Dr. 

 J. S. Kingsley, in his investigations, hardened his eggs by Perenyi's 

 fluid, followed by alcohol of increasing strengths ; this is a process which 

 works well with almost all arthropod tissues. In most cases they were 

 stained entire with Grenadier's alum-carmine, but sometimes Grenadier's 

 borax-carmine or Kleinenberg's hematoxylin was used. In later stages, 

 when the deposition of pigment in the eye interfered with clear vision, 

 the eggs were cut into sections, which were fixed to the slide with 

 Mayer's albumen fixative. After melting the paraffin and allowing the 

 sections to drop into the adhesive mixture, the imbedding material was 

 dissolved in turpentine, and this was washed away with 95 per cent, 

 alcohol. The sections were then covered with a mixture of equal parts 

 of 95 per cent, alcohol and nitric acid, and after ten to fifteen minutes 

 the pigment was removed. The slide was next washed with strong 

 alcohol, and the sections stained deeply with Kleinenberg's hematoxylin, 

 the excess being removed with acid alcohol in the usual manner. The 

 sections were then mounted in balsam. 



Preparation of Ascaris megalocephala.t — Prof. 0. Zacharias, 

 believing that the conjugation of male and female chromatin elements 

 must be a very rapid process, was naturally led to distrust the slow 

 fixing methods hitherto practised, and sought for a better. Fresh 

 females were laid on a piece of wadding damped with 3 per cent, salt 

 solution, covered with another of the same, put under a bell-glass, and 

 incubated at 20° B. for two or three hours. Polar body formation and 

 segmentation are thus stimulated. The separated organs are then placed 

 in a fixing medium, the period being varied according to the age of the 

 different regions of ova, and according to the character of the host. The 

 youngest ova were only exposed for 5-7 minutes, the oldest for at least 

 25. After fixing in a mixture of acids (not yet disclosed), the ova were 

 removed for 2-3 hours to absolute alcohol, and then placed in weaker 

 spirit. Schneider's acetic carmine, and acidified aqueous solution of 

 methyl-green, were also used. The ova were cleared in two volumes 

 of glycerin to one of water. 



Preparing Tape-worms for the Museum and the Microscope,^ — 

 Mr. J. M. Stedman fills a hypodermic, or other syringe possessing a fine 



* Journ. of Morphology, i. (1887) p. 49. 



t Arcli. f. Mikr. Anat., xxx. (1887) pp. 111-82 (3 pis.). Cf. supra, p. 43. 



j St. Louis Med. and Surg. Journal, liii. (1887) p. 291. 



