472 



STUDIES IN SEEDS AND FRUITS 



Soc. Plct. 1908) places the seeds of C. ensiformis amongst his " macro- 

 biotic " seeds with more or less impermeable coats (p. 200). But in 

 the entry in his tables (p. 35) he says that hve out of six seeds swelled 

 without assistance. It is, however, evident that his use of the speciftc 

 name C. ensiformis covers both varieties as well as others, and therefore 

 includes both permeable and impermeable seeds. 



NOTE 6 (pp. 71, 166). 



The influence of the coverings on the drying of permeable seeds. [See also 

 Note I 2 on the time required for drying.) 



This is by no means an easy subject, since the drying r(^gimes of 

 seeds vary much, and an experiment very simple in its operation may 

 be influenced by a number of antecedent conditions. Some oily seeds, 

 like those of Ricinus communis^ are but slightly, if at all, affected in the 

 freshly gathered condition by the removal of the coverings. Thus in 

 the case of two samples of seeds, one just collected from the fruits, and 

 the other gathered seven weeks before, the bared kernels showed no 

 loss of weight, but merely varied about i per cent, in response to the 

 changes in the atmospheric humidity. 



On the other hand, the coverings may be inert in their influence on 

 the drying process, as in the instance of seeds containing in the fresh 

 state an abundance of water. This is the case with the seed of the 

 Horse-chestnut [^Escuhis Hippocastanum\ which, when freshly gathered 

 from the dehiscing capsule, contains about 48 per cent, of water, and 

 dries, as shown in the results given below, more quickly and more 

 completely in its coverings than when it is bared. 



Drying of Seeds from the Dehiscing Capsules of 

 THE Horse-chestnut. 



The weight of a moist seed varies from 200 to 240 grains. In the case of C, I have 

 deducted the weight of the coats ; 25 per cent, in the first, 27 per cent, in the second, and 

 28 per cent, in the third and fourth columns as obtained from other seeds. 



