370 MULTIPLICATION. 



See Schauer's translation of Moouin-Tandon, ' El. Terat. Veget.,* p. 

 245, adnot., and ' Al. Braxm Polyembryonie.' 



Increased nnmber of the cotyledons. Although the pre- 

 sence of one or of two cotyledons in the embryo is 

 generally accepted as a valuable means of separating 

 flowering plants into two primary groups, yet, like 

 all other means of discrimination, it occasionally fails, 

 and, indeed, almost always requires to be taken in 

 conjunction with some other character. There are 

 cases among flowering plants where the embryo is 

 homogeneous in its structure, there are others in which 

 the number of the cotyledons is more than two. Thus, 

 in some seeds of Cola acuminata the cotyledons vary in 

 number from two to five. I have not been able to 

 ascertain precisely whether this multiphcation of the 

 cotyledons is characteristic of all the seeds of particular 

 trees, or whether some only are thus affected. Some 

 fruits that I examined bore out the latter view, as in 

 the same pod were seeds with two, three, and four coty- 

 ledons respectively. 



I have also seen three cotyledons present in embryo- 

 plants oiCorreaj Cratcegus Oxyacantha, Dianthus sinensis ^ 

 Daticus Carota^ Cerasus Lauro-cerasus. De Candolle 

 alludes to a case of the kind in the bean, and figures 

 a species of Solanum with three cotyledons.^ Jaeger 

 alludes to a similar instance in Apium retroselinum ;' 

 Ehrenberg to one in the marigold {Calendula) ;^ Reinsch 

 to an analogous appearance in the beech {Fagus)^ as- 

 sociated with a union of the margins of two out of the 

 three cotyledons, and of those of two out of the three 

 leaves next adjacent.* This fusion seems fi'equently 

 to accompany increase in the number of cotyledons. 

 It was so in the Correa and in the Crata-gus previously 

 mentioned. Some of these cases may be accounted 

 for by chorisis or by a cleavage of the original cotyle- 

 dons, as happens, according to Duchartre,^ in some 



' Organog. Veget.,' tab. 53. Missbild.,' p. 206. 

 ' Ehrenberg, ' Flora,' 1846, p. 704. * ' Flora,' 1860, tab. 7. 

 * ' Ann. Sc. Nat.,' 3 ser., t. x. p. 207. 



