ALMOND. 9 



distilled, yielding the true essential oil of bitter almonds. The cake 

 obtained in the manufacture of oil is a valuable stock food. The 

 shells are employed as fuel or are sometimes finely ground and used 

 to adulterate spices, a practice which can not be too strongly con- 

 demned. Even the hulls need not be wasted, as horses readily learn 

 to eat them and they are a fattening food, as shown by analyses by 

 Forbes and Skinner. 1 The presence of 7.34 per cent of tannin, how- 

 ever, is evidence that some caution should be exercised in using 

 almond hulls as food for domestic animals. 



HISTOLOGY. 



The integument or spermoderm of the almond and related seeds 

 consists of an outside layer of rather large cells, a middle layer of 

 partially collapsed parenchyma cells through the outer portion of 

 which the vascular bundles are distributed, and a delicate inside 

 epithelium usually seen with difficulty. Of these the outside layer 

 is, as a rule, sufficiently distinctive to enable one to determine the 

 species to which the seed in question belongs. Wittmack and Buck- 

 wald, 2 however, do not consider the differences sufficiently character- 

 istic to serve as a means of identification, while Godfrin, 3 on the other 

 hand, states that the peach kernel is easily distinguished from the 

 almond by the structure of the seed coat. 



In the soft-shelled almond the epidermal layer consists of cells often 

 200 p,. 4 irt diameter and seldom less than 100 JJL. It is worthy of note 

 in this connection that Hannig 5 found the diameter of the epidermal 

 cells of the almond to vary from 23 to 124 \L. and a similar disagree- 

 ment with the figures given here occurs in his measurements of the 

 epidermal cells of the peach, apricot, and prune kernels. These epi- 

 dermal cells are usually crowded closely together, but small inter- 

 cellular spaces, in some specimens reaching considerable size, are occa- 

 sionally found. The pale yellow cell walls are moderately thin and 

 smooth, penetrated by pores only over the areas of contact between 

 adjacent cells. Usually a few have thicker walls than others, sug- 

 gesting the stone cells found in the epidermis of the hard-shelled 

 almond, and this is especially noticeable in those strains of soft- 

 shelled almonds having rather thick, firm shells. 



The spongy parenchyma cells of the middle layer of spermoderm 

 resemble in form those of the epidermal layer, but have thinner, 

 mostly colorless, walls and seldom reach a diameter of 100 y.. In a 



1 Forage Products. Arizona Agr. Exper. Sta. Kept., 1902, pp. 268-270. 



8 Die Unterscheidung der Mandeln von ahnlichen Samen, Ber. d. Deuts. Bot. Gea., 1901, 

 19 : 591. 



Les Teguments Seminaux des Angiosperms. Bui. Soc. Sci. Nancy, 1880, p. 147. 



*The micromillimoter or micron, commonly represented by the Greek letter ft (mu.i, 

 equals 1/1000 millimeter, or about 1/25000 inch. 



B Zts. Nahr. Genussm, 1011, 21: 580. 

 55137 Bull. 16012 2 



