4o6 STUDIES IN SEEDS AND FRUITS 



fruits of Iris Pseudacorus were chosen. A hundred embryos 

 were found to make up the weight of a single kernel ; and 

 since the kernel weighed 1-3 grain, this gave -013 grain as the 

 weight of the embryo. It was then ascertained that in point 

 of bulk about 85 embryos went to a kernel, which, interpreted 

 as weight, gave the weight of the embryo as -015 grain, which 

 is 16 per cent, greater than the actual weight determined by 

 the balance. It was then assumed that weight calculated from 

 relative size displayed an error of this amount, but, taking into 

 consideration the fact that the method is at its best crude, and 

 remembering that only approximate results could be looked 

 for, I decided to ignore it altogether and to accept bulk as 

 roughly indicative of weight. 



As it was evident that in very small seeds one would have 

 to rely mainly on the bulk-data, the question arose as to the 

 method of obtaining them. My choice lay between making 

 my own seed-sections and utilising the materials offered by the 

 illustrations in The System of Botany of Le Maout and Decaisne 

 (English edition, 1873) '■> "^^^ ^^e last method was selected. 

 From the sections of seeds there figured I could procure the 

 requisite measurements, obtaining for myself, when needed, the 

 data for the relative thickness of the seed. But in the first 

 place I tested the method by comparing the results obtained 

 by estimations from the figures in the above-named work with 

 those supplied by actual measurements of the seed. They 

 came fairly close together in the case of the seeds of Iris 

 Pseudacorus^ 85 embryos going to make up a kernel by my 

 own measurements of the seeds, and 75 according to the data 

 offered by the illustration of an Iris seed of the same type 

 in the general work. The seeds of the Elder {Sambucus 

 nigra), weighing only -05 grain, were then employed. Actual 

 measurements of a seed indicated that the embryo formed 

 about a tenth of the bulk of the kernel, whilst the d^ta 

 supplied by the figure of the same seed gave the proportion 

 as one-twelfth. 



Still smaller seeds, those of Aquilegia weighing only "03 



