34 STUDY OF NUTS MICEOSCOPIC IDENTIFICATION. 



the ends of the cells, where they become very much thinner. The 

 endocarp is lined with a cuticular layer similar to that of the epicarp, 

 which separates readily from the palisade layer and retains the out- 

 line of the cells. The arrangement of the tissues of the endocarp is 

 shown in cross section. (PL V, fig. 4.) 



The hard mass of tissue in the sinus of the nut consists of thick- 

 walled, extremely irregular cells, united by swollen branches and 

 provided with pores at the area of contact. (PL V, fig. 5.) Else- 

 where the walls are smooth and apparently of even thickness. 



The seed coat is of simple structure, consisting of several layers of 

 parenchyma cells averaging about 40 \L in diameter. Numerous 

 vascular bundles pass in wavy lines through this tissue. The outer 

 layers of the seed coat comprise a soft, pithlike, pink or whitish tissue, 

 thickest at the sinus, and composed of delicate, branching cells. The 

 inner tissue is of a brownish color with polygonal cells and no inter- 

 cellular spaces. 



Viewed in the section, the outer portion of the seed coat appears 

 as a colorless tissue composed of collapsed, thin-walled cells, which 

 expand upon soaking so as to form a layer upward of half a milli- 

 meter in thickness. Vascular bundles occur in the inner part of 

 this tissue, close to the brown layer which follows. The latter, com- 

 posed of about half a dozen layers of cells, has a thickness of about 

 50 to 60 \L. Closely attached to the inner surface of the seed coat 

 is an inconspicuous tissue about 10 \L thick, of collapsed appearance, 

 apparently representing perisperm or more probably endosperm. 



The embryo, which comprises the kernel, consists of the two fleshy 

 cotyledons, bent to one side at the middle and joined at their bases 

 to the conical protruding radicle. A section made at the surface of 

 the kernel shows a remarkably even epidermal layer about 18 (JL thick. 

 In surface view these cells average about 12 to 15 \L in diameter and 

 are often nearly rectangular. The vertical walls are beautifully 

 beaded. The second layer consists of somewhat larger cells, less regu- 

 larly arranged. Further inward the cells increase in size up to about 

 40 [A, and are nearly spherical, leaving very small intercellular spaces. 

 They are -filled with oil globules and oval starch grains mostly 5 to 

 12 |A in length, which strongly resemble a leguminous starch or that 

 of the acorn. (PL V, fig. 6.) 



CANABIUM NUT, OB JAVANESE ALMOND. 



(Canarium indicum Stickm. Family Burseracew.) 



The rich, oily kernels of the canarium nut are much relished by 

 the natives of Oriental countries, but are not much known to Ameri- 

 cans. The nut, which is imported to a limited extent, finds con- 



