Partial Variability of Tricotyly. 449 



unavoidable errors in the samples of seed. In Mcrcit- 

 rialis annua I have for several years recorded the seed- 

 lings which came up from the first seeds that fell exit 

 on the bed. In this species, as is well known, the fruits 

 open suddenly and scatter their seeds about. These counts 

 gave essentially the same results as those obtained later 

 from seeds harvested and sown by hand. I often made 

 use of them to obtain a preliminary idea concerning the 

 extent of the improvement to be expected. 



My custom is to limit the separate harvests to the 

 desired quantity of seed, by cutting back during the 

 period of growth, and by stopping the saving of seed as 

 soon as a sufficient quantity has been secured. For this 

 purpose I have estimated this amount from the result 

 obtained in the first generation, in the case of each species. 

 Moreover I have frequently compared such gatherings 

 with much more extensive ones, obtained either bv not 

 cutting the plants back or by not ceasing to save the seed 

 before all of it was ripe. In this way Aniarantns spc- 

 ciosiis often gave higher values from a smaller harvest, 

 but tlie differences were slight and the exceptions many. 

 Cannabis saliva gave the same values from large plants 

 bearing more than 100 cubic centimeters of seed each, 

 as from average or weaker individuals. In such large 

 crops, saved without limitation and amounting to 80 — 

 110 cc. of seed the average was 11%, but in croi)s of 

 20 — 35 cc. it w^as 14%. The cultures were made in 1S*^)4 

 and the same happened in other years. In Oenothera 

 rubrincrvis the value was seen to decrease as the size 

 of the harvest increased, but only in degrees of one-tenth 

 per cent, on the average, amongst numerous individual 

 trials. 11ic same occurred in ScropJuilaria nodosa. 



This latter s]~)ecies, as well as Silcnc inflafa, is a per- 



