98 



THE AMERICAN MONTHLY 



[May, 



the Journal care to observe these 

 pecuHar changes, they can be well 

 seen in the epithelial of the newt, if 

 they will take the trouble in the spring 

 to get the eggs hatched, and rear 

 the young, and, at different stages of 

 their growth, to make picric acid pre- 

 parations from the tail. The value 

 of killing the animal and soaking the 

 tissues with picric acid is that it acts 

 upon the protoplasm, fixing it instant- 

 ly as nothing else I am acquainted 

 with will do ; as will be shown by 

 the naturally distended blood vessels 

 and well preserved corpuscles, but 

 more especially by the fixed reticula- 

 tion or " intranuclear net-work " of 

 the epithelial cells. 



The claim made by some of high 

 authority, that picric acid prepara- 

 tions will not take and retain car- 

 mine stain, is a mistake, for I 

 have, and so have others here, pre- 

 parations that have been mounted a 

 long time that show the carmine 

 stain as brilliant as when first mount- 

 ed, and far more brilliant than the 

 alcohol preparations of some of the 

 complainants about picric acid. 



A. A. B. 



CORRESPONDENCE. 



To THE Editor : — Some five years 

 ago I received a specimen of diatoma- 

 ceous matter from my correspondent, 

 Mr. G. Morehouse. It proved to be 

 almost pure Cocconies placentida, epi- 

 phytic on a minute, filamentous alga. The 

 alga was so completely covered with the 

 epiphyte as to be itself nearly invisible. 

 In this state it made an interesting study 

 of the mode of growth of this group of 

 diatomaceee. 



A few months ago I placed a portion 

 of the material in water, in which it has 

 been macerating until recently. Then it 

 was slightly washed with soap, put into 

 dilute alcohol, a pippet drop placed on a 

 cover, heated, and mounted in Canada 

 balsam. The result was unexpected. The 

 vegetable matter was partly removed, en- 

 tirely in many places, leaving the diatoms 

 clean and brilliant, but the bulk of them 

 remained adhering together in the same 

 position as when they encrusted the fila- 



ment, as tubes made up of the diatom f rus- 

 tules in all positions. Being transparent, 

 the filament having dissolved away, a 

 much larger number are now visible, thus 

 affording a new opportunity for the study 

 of their growth, which, however, could 

 not have been understood, if they had not 

 first been seen in their natural state. 



If this material had been prepared in 

 the usual manner with chemicals, the 

 frustules would undoubtedly have been 

 detached from each other. It is usually 

 understood that the diatoms secrete a 

 mucous covering. We may infer from this 

 instance that while the mucous is destroyed 

 by chemicals, it is not removed by simple 

 maceration in water, but that it causes 

 the adherence of the diatoms in their 

 natural relation to each other. 



Charles Stodder. 



NOTES. 



— Dr. T. F. Allen, of this city, has made 

 use of a solution for mounting algse, 

 characeae, etc., which preserves the ar- 

 rangement of the cell-contents in a most 

 excellent condition. The solution is pre- 

 pared as follows : 



1. Wood-vinegar, sp. gr. 1.04, 100 pts., 

 salicylic acid, 1 pt. ; shake, and allow to 

 settle. This mixture is named " salicylic 

 vinegar." 



2. For algs mix salicylic vinegar, 1 pt., 

 glycerin, 1 pt., water, 20 pts. 



3. For infusoria mix salicylic vinegar, 

 1 pt., glycerin, 10 pts., water, 40 pts. 



— The liberality and cooperation of the 

 Woman's Education Association enables 

 the Boston Society of Natural History to 

 announce that a Sea-side Laborator}-, 

 under the direction of the Curator, Mr. 

 Alpheus Hyatt, and capable of accommo- 

 dating a limited number of students, will 

 be open at Annisquam, Mass., from 

 June 5th to September 15th. 



Annisquam is situated on an inlet of 

 Ipswich Bay, on the north side of Cape 

 Ann, and is about three and a-half miles 

 by coach from the Eastern Railroad Com- 

 pany's station in Gloucester. The pur- 

 pose of this Laboratory is to afford oppor- 

 tunities for the study and observation of 

 the development, anatomy and habits of 

 common types of marine animals under 

 suitable direction and advice. There will 

 be therefore no attempt, during the com- 

 ing summer, to giving any stated course 

 of instruction or lectures. 



