OG 



Crystals in the Intestines of Artemia Salina. 



cover with thin glass, and apply very slight pressure, so as not 

 to smash the crystals. To my surprise I did not find in any of 

 these a single aigrette, but multitudes of more or less amorphous 

 masses, tending to regular crystalline forms. A few of these 

 masses, but by no means the smallest, are given in the- annexed 

 sketch, and it will be seen from the appended statement of 

 magnification, that they were very small in comparison with 

 the aigrettes in the first specimens. The aigrettes were 

 beautifully shown with a one-fifth objective and second 

 eye-piece, giving a power of 420, while the examination 

 of the amorphous masses was advantageously made with 

 Smith and Beck's one-twentieth and first eye-piece, giving 



X1000 



X1000 



CRYSTALS IN INTESTINE OF ABTEMIA SALINA. 



1000 linear, and manipulated with quite as much facility as 

 the lower power. Although this high magnification was neces- 

 sary for accurate examination, the amorphous particles could be 

 discerned with as low a power as two hundred and thirty when 

 the attention was directed to them. In many cases the intes- 

 tine was nearly filled with these particles, which in the aggro- 

 gat' l«'«l in quantity the dark fcecal matter. 



The approrimatioD to regular form of crystals varied greatly 

 in different individuals. In some, every particle might be de- 

 scribed as amorphous ; in others, many imperfect crystals could 

 be seen, and in one I noticed two regular hexagons j one of them 

 such as would be obtaiued by inscribing a hexagon in a circle, 



