482 



BROOKLYN BOTANIC GARDEN MEMOIRS 



shown in no. 4, as well as in seedlings having only one cotyledon, as 

 shown in nos. 16 and 17. Such plants usually die soon. In some cases, 

 however, adventitious buds arise, but as far as observed these make 

 only a feeble growth. The drawings i6b and lyb show such feeble 

 adventitious growth of seedlings nearly three months old, at which 

 time many sister plants had rosettes measuring ten inches in diameter. 



. ^^ 



V. 



//A 



Fig. I. Young seedlings of the variety red- leaved Treviso. Scale about one- 

 half natural size. 



I and 2. Two normal separated cotyledons with plumule. 



3. Two cotyledons, both somewhat crumpled. 



4. Two cotyledons; no plumule. 



5. Cohesion at base of cotyledons only. 



6. Cohesion at base of cotyledons; one crumpled. 



7. 8, 9. Decided cohesion. 



10, II, 12. Only one cotyledon present. 



13. Two cotyledons; separation involved some lesion. 



14. Much crumpled and poorly developed cotyledons. 



15. Some cohesion at base. 



i6a. Single cotyledon; no plumule, b. Same seedling two months later with 

 adventitious bud. 



17a. Single much crumpled cotyledon with seed coat attached at apex; no 

 plumule, h. Same seedling two months later. 



18. Much fusion of cotyledons. 



19, 20. Decided lobing of one cotyledon. 



The growth interrelations of reduction or fusion of cotyledons with 

 duplication in the main axis are not clear. In the former there is 

 a fusion or reduction in the number of organs normally formed; in 

 the latter there is a tendency to the production of two main stems 



