Hcnii-Syncotyly, Syncotyly, Auiphi-Syncotyly. 461 



])itc]iers by splitting them up along one side with a sharp 

 knife, as soon as I saw that the plant would not grow 

 without this help. By this means I succeeded in bringing 

 the plants to flower, but they were weak, thin-stemmed 

 individuals. 



The growth of the plumule is often entirely sus- 

 pended, both in ordinary unilateral syncotyls and in 

 pitcher-like structures. In such cases the seedlings live 

 much longer than usual, the cotyledons grow to a great 

 size, often twice the normal, but finally the plant dies 

 without producing a stem. This occurred frequently 

 in Hclianthus annuus and Dahlia variabilis, and less often 



Fig. 92. Polygonum Convolvulus. Instances of tri-syn- 

 cotylous seedlings with various degrees of splitting and 

 fusion. 



in Penstcrnon gcntianoides and Cannabis sativa. In the 

 two latter species one or two leaves were sometimes de- 

 veloped, but after that the terminal bud ceased to grow, 

 whilst those leaves attained an abnormal size and thick- 

 ness (Fig. 93). In such cases the question arises whether 

 the inhibition of the growth may not, both here and 

 elsewhere, have some other cause also. 



Syncotyly may be combined with tricotyly, and since, 

 as we have seen, the fluctuating variability of both pre- 

 sents a long series of forms, the multiformity will be 

 much greater still in the series of the so-called tri-syn- 

 cotyls. Thus, for instance, in Polygoniun Conrolvulns 



