Heini-Syncotyly, Syncotyly, AmpJii-Syncotyly. 459 



cotyls and types in which the fusion has extended to the 

 very tip- The lesser degrees of fusion are usually rarer 

 than the greater, and, therefore, in order to get a fairly 

 complete series of transitional forms, cultures from the 

 seeds of selected individuals are required. It is often 

 very difficult, especially in forms with stalked cotyledons, 

 to distinguish between the lowest grades of fusion and 

 pure dicotyls. If the crops are recorded before the 

 cotyledons and their peduncles have grown to their full 

 extent, it may easily happen that occasional seedlings. 



Fig. 90. Oenothera glauca. Syncotylons seedlings. A and 

 B, ordinary syncotyls ; C and D, pitcher-shaped syncotyls 

 or amphi-syncotyls. 



which, after further growth, will prove to b hemi-syn- 

 cotylous, are mistaken for dicotyls. 



The hemi-syncotyls constitute the minus variants of 

 the series, the corresponding plus variants being the 

 amphi-syncotyls of double or two-sided syncotyls (amphi- 

 cotyls). In these latter cases the cotyledons are fused 

 on both sides, often more on one side than the other, 

 sometimes equally high on both sides. The cotyledons 

 constitute a pitcher (Fig. 90 C and D, and Fig. 91) 

 which is either cylindrical or urn-shaped or disc-shaped, 



