Chap. III. GILIA MICRANTHA. 119 



flowers the difference in length between the pistils of the 

 two forms was certainly greater, but they were not actu- 

 ally measured. In the short-styled flowers, whether large 

 or small, the stigma is seated low down within the tube of 

 the corolla. The papillae on the long-styled stigma are 

 longer than those on the short-styled, in the ratio of 100 to 

 40. The filaments in some of the short-styled flowers were, 

 to those of the. long-styled, as 100 to 25 in length, the free, 

 or unattached portion being alone measured; but this 

 ratio cannot be trusted, owing to the great variability of 

 the stamens. The mean diameter of eleven pollen-grains 

 from long-styled flowers, and of twelve from the short- 

 styled, was exactly the same. It follows from these several 

 statements, that the difference in length and state of sur- 

 face of the stigmas in the flowers is the sole reliable evi- 

 dence that this species is heterostyled ; for it would be rash 

 to trust to the difference in the length of the pistils, seeing 

 how variable they are. I should have left the case alto- 

 gether doubtful, had it not been for the observations on the 

 following species ; ^nd these leave little doubt on my mind 

 that the present plant is truly heterostyled. Professor 

 Gray informs me that in another species, G. coronopifolia, 

 belonging to the same section of the genus, he can see no 

 sign of dimorphism. 



GiLiA (Leptosiphon) micrantha. 



A few flowers sent me from Kew had been somewhat in- 

 jured, so that I cannot say anything positively with respect 

 to the position and relative length of the organs in the two 

 forms. But their stigmas differed almost exactly in the 

 same manner as in the last species ; the papillse on the long- 

 styled stigma being longer than those on the short-styled, 

 in the ratio of 100 to 42. My son measured nine pollen- 

 grains from the long-styled, and the same number from the 

 short-styled form; and the mean diameter of the former 

 was to that of the latter as 100 to 81. Considering this dif- 

 ference, as well as that between the stigmas of the two 

 forms, there can be no doubt that this species is hetero- 

 styled. So probably is Oilia nudicaulis, which likewise be- 

 longs to the Leptosiphon section of the genus, for I hear 

 from Professor Asa Gray that in some individuals the 

 10 



