i6o American Quarterly Microscopical Journal. 



the value of the laboratory in the study of the marine fauna of that 

 location. The laboratory is intended to furnish advanced students 

 with opportunities for original investigation ; to provide material for 

 winter work ; to give practical instruction in the methods of marine 

 zoological work ; and to increase our knowledge of the zoology of the 

 Chesapeake. As to the scientific results of the first year's labor , they 

 are highly creditable and promise well for the future. Mr. H.J. Rice 

 studied the development of Amphioxus, and was able to make valuable 

 additions to our knowledge of this interesting vertebrate, which is 

 thought to be a rarity on this coast. Lingula was studied under particu- 

 larly favorable conditions, and Mr. Brooks was able to follow its 

 development from a very early stage up to the adult form. 



LABORATORY NOTES AND QUERIES. 



1. Very excellent permanent preparations of the red blood-corpus- 

 cles of Amphibia may be made by Ranvier's method, as follows : 

 Some blood is allowed to drop from a wound into about 200 times its 

 volume of a saturated picric acid solution. After a few minutes the pic- 

 ric acid is carefully poured oflf, leaving most of the corpuscles at the 

 bottom of the dish ; a solution of picrocarmine is then poured over 

 them, and allowed to stand a day or two. The picrocarmine is then 

 poured off and the sediment put into acid glycerin (glycerin 100 

 parts, acetic acid i part). The corpuscles so treated will last a long 

 time, and may be mounted in the acid glycerin at any time. The nu- 

 clei of the corpuscles are stained bright red, and the body light yellow. 

 Corpuscles of Menobranchus, which are about twice as large as those of 

 the frog, prepared in this way nearly a year ago, appear perfect as 

 ever. 



2. When tissues are imbedded in paraffin for making sections, the 

 imbedding mixture gets into the meshes of the loose, external, con- 

 nective tissue, and the mouths of the ducts, glands, etc., so that the 

 outlines of the sections are greatly obscured, unless they are put into 

 some medium that dissolves the parafiin. If they are to be 

 mounted in glycerin, or some other fluids, this cannot be done except 

 by tedious manipulation. The imbedding mixture may be kept en- 

 tirely away from the tissue, by first dipping it into thick gum-arabic, 

 and then putting it into strong alcohol for a short time. The alcohol 

 hardens the gum, which forms a protecting coat, and also a mechanical 

 support for the loose connective tissue around the outside. The gum 

 may be dissolved from the sections by immersing them for an hour or 

 two in 2K, per cent, alcohol. Sections prepared in this manner maybe 

 cleared, and mounted in balsam or damar, by the usual method. 



3. In a very able article upon the preparation of rocks and fossils 

 for microscopical examination by R. Fritz Gaertner, in the April num- 



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