46 riTTONIA. 



the two individual members of each lying parallel to one 



another. 

 There is no floral organ more depended on by systematic 



botanists than the calyx. Its usefulness as furnishing the 

 most unfailing characters for the genera in many an order, 

 and even ordinal characters, is recognized everywhere. In 

 this family the sepals are four, distinct, hypogynous and 

 imbricated. To this diagnostic phrase Sitbularia becomes, 

 as above noted, the most remarkable exception, in that its 

 calyx is gamosepalous. The sepals in a few genera are said 

 to exhibit the valvate mode of SDstivation, Commonly the 

 four sepals are in somewhat unequal pairs, the laterals bei«g 

 a little smaller than the other tAVOj but the difference is 

 usually insignificant. In some Californian species, however, 

 the laterals combine with the upper one in such wise that, 

 in the expanded flower the three form as it were a broad and 

 somewhat concave upper lip widely separated from the soli- 

 tary lower one ; so that this organ is more bilabiate than the 

 corolla is in the same species. In Slrej)ianthus ][>olygaloides 

 while the petals are reduced to insignificant almost filiform 

 organs without color, the large yellow calyces completely 

 simulate a papilionaceous corolla insomuch that none but 

 an experienced botanist would suspect the plant of being 

 a crucifer at all, unless he should see its pods or taste its 

 herbage. In this most anomalous flower the lower sepal, 

 quite large, is boat-shaped and keeled ; the t^vo laterals are 

 so much reduced in size as to be easily overlooked ; the upper 

 one, broadly obovate, is, in the bud, conduplicately folded 

 down over all the others, completely concealing them, while 

 in flower it is spread out and stands erect, precisely like the 

 large banner of a pea-blossom. 



Let me conclude these discursive paragraphs on the floral 

 morphology of the Crucifercne by an illustration taken from 

 the experience of a public instructor in Californian botany. 

 "With the purpose of leading his students to an acquaintance 

 with natural families, he will select this one among the first, 

 both on account of the naturalness of it, and because of the 



