Io8 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



apparently different; here, also, variations attributed to 

 environment are shown to be constant. In the garden, too, 

 strains, which from a botanist's standpoint seem scarcely 

 distinguishable, show marked differences in vigor, flower- 

 ing time, or immunity from disease. 



It is a peculiarity of our liliaceous plants, that as a rule in 

 a given locality there is little variation from a well marked 

 type, as little, indeed, as may be found between flowers 

 growing upon the same plant. Hundreds and thousands of 

 flowers may be picked, all conforming closely to this type. 

 In another locality, the same species will be found marked- 

 ly different. The difference between the forms in the two 

 localities may be slight, consisting merely of a marking or a 

 slightly varying leaf, habit, or gland ; yet the variant, once 

 noted, is found to be constant. In Calochortiis color forms 

 are frequent, the flowers from one bulb retaining the same 

 tints under any and all conditions. The difference between 

 forms from different localities is rather that which florists 

 designate by the word "strain" than what is usually under- 

 stood to constitute a botanical species or variety. 



In cultivation it has frequently been found that a very 

 slight variability in strains is accompanied by a marked 

 constitutional difference. In two beds of Calochoj'tus venus- 

 tus, planted in the same soil, and separated only by a thin 

 board, it would puzzle a botanist to state wherein the plants 

 vary. They come from widely separated localities, and the 

 difference is one more easily detected by the eye than con- 

 veyed by words. In one bed, two-thirds of the leaves are 

 already destroyed by mildew (Botrytis), while in the other, 

 not one leaf is injured; and such is the case whenever and 

 wherever the two are planted. Many similar instances 

 occur in other species, but a single one is sufficient to show 

 that the slight variations which the eye detects are not the 

 only ones. 



Such strains are present in nearly every species of Calo- 

 chortiis. The range of a strain may be very local — a few 

 miles square — or it may be found over half the length of a 

 state. In Calochortus vemistus one strain runs through all 



