J 76 



Recess disco- 

 vered in a vraU 

 nuc 



The walniit 

 has from four 

 to nine cotyle- 

 dons. 



Corculum of 

 the vralnut. 



Horse chest* 



mit,- 



«N THE STRUCTURE AND CLASSIFICATION OF SEEDS. 



few dicotyledons. Dissecting a very unripe walnut, in 

 order to discover the course of its nourishing vessels in the 

 corculum, I perceived a recess I had not before noticed. 

 Desirous of knowing what it contained, I fastened a double 

 magnifier of great power over it, so that I might scrape its 

 interior with a fine lancet. I drew out three diminutive 

 points, which in the solar microscope I soon found to be 

 perfect cotyledons. I then dissected another vvalnut, and 

 discovered four much larger, which covered the lower part 

 of the corculum like a festooned curtain. These I had be- 

 fore seen, and taken for scales of the kernel, so assured was 

 I, that there could be but tivo cotyledons. Hence the mis- 

 chief of trusting to any person, or thing, in the study of ntt' 

 ture, but herself. I then divided the corculum as usual, 

 and found the common cotyledons : in one walnut there- 

 fore I found nine, and in above 60 more I discovered from 

 four to seven. I doubt not many more may be seen in aa 

 older waln'ut. I shall now give the picture of the corcu- 

 lum of the walnut, which will better enable the reader to 

 understand the description of the ditferent classes, and of 

 the number of cotyledons that belong to ea|:h, with all the 

 rest of its arrangement, 



Plate V, fig. 1, represents the corculum of the walnut 

 when covered by the upper colytedons : x x two of the co- 

 lytedons taken off. Fig. 2, the corculum or heart of the 

 walnut when divided, showing what have always been reck- 

 oned cotyledons at c c, and the breast with the teats d d. 

 Fig. 3. the corculum turned so as to show the back. /"The 

 recess. 



After opening a qunntity of walnuts, it may well be ima- 

 gined, that I was impaiient to see whether a recess was to be 

 found in all seeds; and if other seeds had these additional 

 cotyledons. The first I tried was the esculus, which had 

 exercised my patience by constant dissections for a long 

 time, in search of them. But I had now found a clew, and 

 discovered therefore 4 ; though from the peculiarly uneven 

 formation of its pocket, it was not till after a pretty long 

 search. I m ust therefore recal the declaration in my last paper, 

 nor shall I ever fail to do so, when I find myself mistaken ; 



seeking 



