MISCELLANEOUS NUTS. 33 



quite inactive. Buchheim * took three or four drops without noticing 

 any effect, and Basiner 2 gave large doses to cats without producing 

 fatal results. 



It is customary to roast cashew nuts preparatory to eating. This 

 process results in ridding the shells of cardol as well as in improving 

 the flavor of the kernels. Cashew nuts so prepared are of the high- 

 est quality, but although imported to some extent for the use of con- 

 fectioners they are not well known in this country. The writer has 

 examined a sample of the unroasted nuts, which contained 30 per 

 cent of kernels. 



Histology. Since no reference to the minute structure of the peri- 

 carp could be found in the literature, the subject was investigated in 

 some detail. A cuticular layer 6 [i in thickness covers the surface of 

 the epicarp, separating easily from the palisade layer underneath in 

 such a way as ta retain the outlines of the cells composing that layer. 

 A careful examination, therefore, is necessary in order to demonstrate 

 the absence of a cellular structure in the cuticle itself. The palisade 

 tissue consists of columnar cells 40 to 50 y* in length and about 10 pi 

 in diameter, which have moderately thick walls provided with longi- 

 tudinal slitlike pores. (PL Y, fig. 3.) Viewed from the outer surface 

 (PI. V, fig. 1), they are seen to be polygonal, and in some cases, 

 especially upon focusing downward, the walls appear quite sinuous. 

 The walls are thickest near the inner extremity of the cells. The 

 palisade layer is penetrated at intervals by stomata 40 to 50 [A in 

 length, which are sunken slightly below the general level of the 

 surface. Underneath the guard cells columnar cells are lacking and 

 a small respiratory chamber is noticed. Adjacent to the palisade 

 tissue are 10 or more layers of thick-walled parenchyma cells, which 

 in turn give place to the mesocarp tissues, larger cells, fibers, and 

 vascular bundles, with which are associated the large oil-containing 

 cavities already mentioned. 



Toward the endocarp are found tissues similar to those beneath 

 the epicarp. There are 6 to 10 layers of thick-walled, somewhat elon- 

 gated parenchyma cells, similar to those which underlie the palisade 

 layer of the epicarp and quite sharply marked off from the typical 

 mesocarp tissue. At intervals those lying next the palisade tissue 

 of the endocarp have their walls so much thickened as to form stone 

 cells. 



There are two layers of palisade cells, the first of which consists 

 of cells only 20 to 25 \L in length, while in the second or inner layer 

 the cells are 350 to 375 p. in length and 10 to 20 jx in diameter. 

 (PL V, fig. 2.) The lumen is small and the walls thick, except at 



1 Rof. in Proc. Amer. Tharm. Assoc., 1874, 22 : 15G. 

 2 Loc. cit., pp. 60-62. 



