SIR J. LUPBOCK — rnXTOBIOLOGICAL OBSEUTATIO^"S. 395 



Strepfocarims Bexii affords, perhaps, the most remarkahle case. 

 The cotyledons are at first small, rotund, and shortly petiolate. 

 Soon, liowever, one of them begins to grow, and becomes an 

 at first ovate, then oblong, and finally pandariform, obtuse, 

 entire, persistent leaf, attaining a length of more than 18 inches. 

 The other cotyledon retains the original form, and soon drops off. 

 In some specimens, however, both cotyledons retain their original 

 form, and it is the first true leaf which develops. 



In the cultivated form of the Mango, the cotyledons are di- 

 vided into more or less irregular lobes ; and in a specimen kindly 

 given me by Mr. Eidley, one of the lobes developed into an inde- 

 pendent plant. 



In (Enothera and some allied species, as already mentioned, 

 the. full-giown cotyledons have a terminal lobe, "which is, in 

 reality, the original cotyledon, while the larger, basal part is due 

 to subsequent growth. I hope to describe these more fully in a 

 future memoir. 



Concluding ItemarJcs. 



• The conditions under which the seedlings are grown naturally 

 exercise some influence on the form of the leaves, Tor instance, 

 in Miiniihis lufeuSy if the seedlii _ 

 leaves are shortly stalked and deltoid, while the primary nodes 

 are but little developed ; on the contrary, if they are more crowded, 

 the internodes and petioles are longer and the leaves are oval. 

 In the Primrose we find an arranijemeut which almost seems 



as if it were intended to give the seedling some power of loco- 

 motion. The caulicle is sometimes horizontal, and tlirows out 

 strong adventitious roots, the upper part, however, becoming 



vertical as usual. 



As a general rule, the first buds produced by the seedlings are 

 in the axil of the leaves, or more rarely of the cotvledons. In 

 some species of Linaria^ however, the caulicle itself throws out 

 one or more buds which develop into branches. The advantage 

 of this may be tliat, if the main shoot is crop])ed or broken even 

 down to the root, the plant is capable of throwing up another 



stalk. 



"We thus find an almost inexhaustible scries of beautiful adap- 

 tations to purpose. On the otherhrmd, tl^cre arc not wanting cases 

 in which it would seem that the adaptation is not complete, or that 



