]g2 MECHANISM OF LEAF«STALK9. 



Fig. 2 is the plant: B B is the upper gatherer, but it has 

 instead of the under one a stipula, which seems by some 

 means (which I have not yet been able to comprehend) to 

 serve instead. All the trifoliumsand numbersof the diadel- 

 phian plants, have it thus. Fig. 3 shows this part dissected 

 and explained. I have never found the balls zz except in 

 the medicagoes, and not in all of these. There is not any 

 thing more curious than the substance of which the balls 

 Formation of are formed. It strongly resembles the matter of the bark 

 the balls, without the inner bark vessels, is extremely watery, is the 



first part that decays, and appears to serve no other purpose, 

 than to fix the string in its place. It is curious, that at f, 

 where the knot comes, there is a fastening which passes en» 

 tirely through the plant. The gatherers m and n at the 

 Form of the side have no balls. There is another kind of a gatherer of 

 everlastijij ^ ^.^^y curious form, which is found in the papilionaceous 

 tribe. It has but one ball; but the same matter, being 

 collected into a thick lump, is folded into creases (see fig, 

 4, and the dissection fig, 5, p 9 ) ; and have a ball in a semi- 

 circular socket ; it turns it to one crease, or the other, by 

 means of the spiral wire. Fig. 5 better displays this, 

 being a side vie\v, and showing how it turns to the right or 

 left, by taking the upper or lower crease, which of course 

 turns the leaves nearly a whole circle. Fig. 6 shows the string 

 A stranKC mis^ when drawn tight in the gatherer. This will serve to prove 

 uke. the thorough mistake of those physiologists, who pretend, 



that the different parts of a plant may be changed for each 

 other, and make a peduncle or leaf take root. Nature does 

 not execute her work in this careless manner, each part has 

 its separate mechanism, than can perform only the part as-* 

 signed. If a flower bud is concealed in the peduncle, it 

 may by accident grow, since the lower port of the gatherer, 

 which joins the stem, is full of flower buds: but then it is 

 these that grow, and not the leaf-stalk ; nor can there be 

 any thing more different, than the peduncle stem, 



1 shall give no farther example this time, 9s what I have 

 already said will be, I hope, sufficient to make what I have 

 drawn understood, and to give some idea of the mechanical 

 jnanHgement of this part of most plants; accounting for 

 the beautiful arrangement of theleaves of trees : and proving, 



npt 



