iQ ON THE STRUCTURE AND GROWTH OF SEEDS- 



Explanation of the Plates, 



Explanation of Plates I and 11. Fig. 1. The seed vessel of the horse 

 ihe plates. chestnut, cut open horizontally* a, a, a, a, the impregnat- 

 ing vessel, or vessel of life, proceeding from the interior of 

 the seed vessel, k, k, the string that stretches to attain the 

 heart, and which, I think, is mistaken for the radicle. 

 b, b, b, b, the nourishing vessels (marked by dotted lines 

 only, to dibtinguish them), which always proceed from the 

 exterior of tlie seed vessel, d, d, d, d, the pocket. 



Note. Similar letters of reference denote the same parts 

 in all the figures. 



Fig. 2. Half a similar seed vessel cut longitudinally, 

 showing the first appearance of the seed vessel in the bud of 

 a female flower. 



Fig. 3. The seed of the horse chestnut. Fig. 4, that of 

 the peach, and Fig. 5, that of a grass, as they first appear 

 in the bud of the flower, c, the corculum. e, the cuticle* 

 or outer skin of the kernel. The seed of the peach is deli- 

 neated in the seed vessel; the others are taken out of it. 



Figs. 6, 7, 3. The same seeds in their second stage of 

 growth. 



Figs. 9, 10, 11. The three seeds in their third stage, when 

 impregnated; the pocket joining the corculum, and the 

 string k disappearing. 



Figs. 12, 13, 14. The seeds in their fifth stage: the cor- 

 culum perfected, the seminal leaves almost complete, and 

 the nourishing vessels on both sides of the seeds. 



Figs. 15, l6, 17. The three plants, showing only the em- 

 bryo of the chestnut and peach. This is now as complete 

 as it ever is, till placed in the ground in the seed. It is 

 given thus, to show, that there is no radicle to it; and that 

 the root, which will grow as soon as it is placed in the ground, 

 can proceed only from .r. This is easily seen, by comparing 

 these with the plants where the root is annexed, which is 

 merely filled out, and grown longer; and where the heart 

 is still to be found, marked by a dotted circle, g, g, the 

 cotyledons, i, i, the primordial leaves. 



Figs. 18, ly. The bean and its embryo from Dr. Smith. 

 g, the cotyledons, h, the holders; which show how little 



they 



