1U8 PROCEEDINGS OF SOCIETIES. 



to even as much aa 90° C. The form-specios in the gatherings, 

 or those whose identity is recognisable without fructification, 

 were absolutely the same in every respect to their congeners at 

 home; so, no doubt, would the others prove to be, had they been 

 in fruit. Mr. Archer hoped to revert on another occasion to 

 the forms which had presented themselves in this interesting 

 gathering. 



Crystals from a Cactus. — Dr. Moore showed crystals from the 

 cells of an unknown species of Cactus, of handsome appearance, 

 probably of oxalate of lime ; they produced rotund groups, the 

 crystals radiating from a common centre, their facetted extremi- 

 ties forming the superficies of the globe. Mr. Tichborne under- 

 took to examine these in a chemical point of view. 



Amoeboid movements of corpuscles of f'Og''s blood. — Mr. B. 

 Wills Kichardson made a very satisfactory demonstration of the 

 ' amoeboid ' movements of the white corpuscles of the frog's 

 blood and of the corpuscles charged with refractive granules. 

 The movements were truly amoeboid and highly characteristic ; 

 the refractive granules likewise were seen in active motion in each 

 amoeboid mass containing them. Several of these were seen to 

 move across the field, and in doing so passed, on more than one 

 occasion, either over or under stationary red blood-corpuscles. 

 Two of the granule-containing amoeboid corpuscles, when moving 

 in opposite directions across the field, came in contact with one 

 another. Their apposed surfaces then became parallel, and the 

 corpuscles themselves were carefully watched by some of the 

 members present to see if they would "conjugate" or coalesce. 

 Instead of doing so, however, they immediately separated, and each 

 retraced its course to the portion of the field whence it came.. 

 The stage used for the occasion was an ordinary Strieker's hot- 

 stage, made and slightly modified for Mr. Eichardson by Spencer, 

 of Grafton Street, Dublin. The blood, when taken from the frog, 

 was at once placed on the glass and with a very thin cover. To 

 prevent evaporation a little spermaceti oil was applied with a 

 fine sable pencil to the margin ; this was done sparingly and very 

 carefully, in order that the oil might not run in. The objective 

 used was -^" Eoss, but probably a -Jg" or -^^j" would be a better 

 power for demonstrating the movements of the refractive 

 granules to those who might be inexperienced in microscopical 

 observation.. 



