STRUCTURE.] BIFORINES CLESTINES. 99 



Morren found the power of emitting their raphides pre- 

 served by these bodies after having undergone 6 of cold of 

 Reaumur (18 Fahr.), and he therefore concludes that the phe- 

 nomenon is, as Turpin supposes, a mere physical action 

 produced by endosmose, and not a vital action. 



He distinguishes from Biforines under the name of destines 

 those well-known large cells in which Raphides, or acicular 

 crystals, are deposited in some plants. He finds that in the 

 Plantain (Musa paradisiaca) the destine is produced among 

 oval tissue of the divisions of the air-cells in the leaves of 

 that plant, and that for a long time after the appearance of 

 crystals in the inside, it preserves its oval figure. So long as 

 it remains attached by a single point to the cells of this par- 

 tition it retains that form, but by degrees the surrounding 

 tissue alters into actinenchym, or starry tissue, and then its 

 adhesion to the cells from which it receives its food takes 

 place at several different points ; whereupon in augmenting 

 in size and gaining a much greater capacity than the sur- 

 rounding actinenchym, it attaches itself to the rays of the 

 latter by legs or peculiar extensions, which may amount to 

 the number eight or ten. But if it is formed at the borders 

 of the prismatical tissue of the partitions, it acquires the 

 form of a cylinder with two beaks. He regards destines as 

 analogous to biforines, but differing in not possessing the 

 apertures required for the ejaculation of their contents under 

 the influence of endosmosis. (Observations sur I' Anatomic 

 des Musa, in the Bulletin de VAc. R. deBruxelles, VI. No. 3.) 



In the last edition of this work, the late lamented Mr. 

 Quekett gave the following excellent account of Raphides, 

 which I reprint because of its intrinsic excellence, although 

 it is in some respects a repetition of the previous observations. 



General Appearance. Raphides are most frequently ob- 

 served under two forms, appearing in one instance as trans- 

 parent acicular crystals, which are either distinct from each 

 other or united into a compact fibrous bundle, and in the 

 other instance as small bodies composed of many crystals 

 which radiate from the same centre, thereby forming a more 

 or less spherical mass. 



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