MISCELLANEOUS NUTS. 29 



consists of oil and aleurone grains. The latter are oval and quite 

 regular in shape, with a crystalloid and one or two comparatively 

 small globoid bodies. They occasionally reach a length of 12 to 15 pi, 

 but those measured averaged only about 6 p. 



BRAZIL NUT. 

 (Bertholletia noMlis Miers, 1 Family Lecythidacece.) 



The Brazil nut is the seed of a large South American tree which 

 has been found too tender to thrive in any part of the United States. 

 B. excelsa Humb. and Bonpl. produces a similar nut. The nuts owe 

 their angular form to the fact that they are borne in dry pericarps or 

 shells, each of which contains about 20 nuts packed closely together. 



In addition to B. nobilis and B. excelsa, edible nuts are produced 

 by a number of other trees of the same family, especially those of the 

 genera Lecythis and Grias. L. usitata Miers yields the sapucaia nut, 

 called also paradise nut, which has not yet become of great commer- 

 cial importance, though it is of more delicate texture and finer quality 

 than the Brazil nut and will doubtless meet with considerably greater 

 demand in the market when better known. 



The Brazil nut is one of the staple nuts on the American market 

 and is too well known to require further description. The kernel, 

 which comprises about 50 per cent of the nut, is firm, oily, and of 

 good quality. The writer obtained 51.4, 52.8, and 52.9 per cent of 

 kernels from three samples of Brazil nuts purchased in the Wash- 

 ington markets. 



Histology. Since the structure of the hard seed coat of the Brazil 

 nut is described by Winton 2 further reference to it is omitted from 

 this account. The inner brown tissue is composed of a number of 

 layers of flattened cells, circular in outline and about 50 \L in diameter. 

 The kernel, which frequently adheres to this tissue so closely as to 

 be separated from it with difficulty, consists of the embryo surrounded 

 by a layer of endosperm 40 to 50 \L thick, which is composed of 

 a double layer of angular cells. The embryo itself is peculiar in 

 that the radicle is very largely developed and is the place of storage 

 of reserve food. The radicle is plainly differentiated into cortical 

 and medullary tissues separated by a layer of procambium, along 

 which rudimentary vascular bundles are arranged at intervals. The 

 epidermal cells do not exceed 20 [i in diameter. The cortex consists 

 of rather loosely arranged, approximately spherical cells varying 

 from the size of the epidermal cells up to 80 JJL in diameter. They 

 are not arranged in layers, but the number of cells in a radial line, 

 which amounted on the average in specimens examined to from 10 



1 Young, Pomona J. Econ. Bot., 1911, 1 (3) : 122-127. 



2 Microscopy of Vegetable Foods, 1906, p. 312. 



