190].] NATURAL SCIENCES OF PHILADELPHIA. 453 



The structure, as well as the mode of formation, of spherites 

 and sphere-(!rystals is apparently the same. The mode of forma- 

 tion is, furthermore, apparently the same whether observed in 

 nature or as carried on artificially. The different stages in their 

 natural formation can be followed comparatively easily in those 

 parts of plants containing hespcridin (as the epicarp of citrous 

 fruits) or inulin (as roots of artichoke, etc.). It is interesting to 

 compare these crystals or spherites with those formed artificially 

 by evaporation of solutions of inulin or hesperidin. It is also 

 instructive to compare the natural oxalates, phosphates, and car- 

 bonates of calcium Avith those formed artificially by precipitation of 

 soluble calcium salts with alkaline oxalates, phosphates or car- 

 bonates. 



After a comparison of the artificially produced spherites or 

 sphere- crystals with those formed naturally in the plant, one cannot 

 but conclude that there is a play of similar forces in their forma- 

 tion. 



Furthermore, if we examine the crystal masses remaining in a 

 watch-crystal after the spontaneous evaporation of solutions of 

 various substances, under varying conditions of temperature, etc., 

 we observe not only the formation of crystals which resemble those 

 produced in the plant cell, but other rather striking forms of com- 

 bination which are very suggestive indeed; leading one to a com- 

 parison of the arrangement of the products of crystallization with 

 the apparent multiplicity of forms found in plant life. Indeed, 

 the arrangement of the crystals in such a watch-crystal reminds 

 one of the appearance of our woods in winter, when the absence 

 of leaves permits the observance of fundamental lines of develop- 

 ment in shrubs and trees. 



If we take an alum solution (such as a Delafield's H^matoxylon 

 Solution), dilute it with water and allow it to evaporate sponta- 

 neously in a watch-crysl al, the result will be the formation of con- 

 centric rows of acicular crystals Avhich show an analogy to the 

 structure of the wheat starch-grain after treatment with the re- 

 agents mentioned. 



The crystalline residue from a cocaine solution resembles a group 

 of sclerenchyma cells in transverse section, the individual sphere- 

 crystals resembling single cells, the portion corresponding to the 

 wall being made up of radiating acicular crystals which even join 



