J/ 







Tricotxious Races. 



the same culture from the seeds of a single seed-parent. 

 This is especially the case in Anfirrliiniiin iiiajiis and 

 ScropJiularia nodosa, in which species I have often pre- 

 ferred as seed-parents, the tricotyls, whose first whorls 

 were trimerous. Nevertheless they have not, as a rule, 

 proved the better qualified to continue the character of 

 tlie race. Further instances are afforded by Dipsaciis 

 sylvestris, Lychnis fidgcns, Dracoccphaluin nioldavicunu 



Dianthus harbafus and so 

 on. Tn the spring of 1887 T 

 had some tricotylous seed- 

 lings of Acer Psetido-Plata- 

 niis: two of them are now 

 high trees, whose trunks bear 

 their branches in trimerous 

 whorls. 



The lateral branches of 

 ternary main stems tend, as 

 a rule, to revert to the de- 

 cussate arrangement. Sub- 

 terranean runners, (for in- 

 stance in Valeriana officina- 

 lis) and the secondary stems 

 which are produced at the 

 Dianthus barbafits), afford, 



Fig- 75- FciStts syhatica. Tri- 

 cotylous seedlings. A, with a 

 ternary whorl of the first 

 leaves ; B, with a leaf with 

 two apices and a divided vein. 



level of the ground (e. g.. 



however, numerous exceptions. 



In tricotylous cultures, dicotylous individuals some- 

 times become ternary later. Thus I possess a plant with 

 ternary whorls of Aesculus Hippocastanuni (now 13 

 years old), which only had two cotyledons, and from 

 the same crop a plant which was tricotylous but has since 

 produced leaves on the decussate plan only. In ]:)Otli 

 specimens the change in the disposition of the leaves 



