Oi LETTER XXX. 



and is hardly a mark of affinity, but rather a specific 

 quality; thirdly, that many Cactuses are climbing- 

 plants, although they have no tendrils. These points 

 being settled, remark in the next place, that both Cac- 

 tuses and Gourds have succulent fruit; that their seeds 

 are numerous, and attached to the sides of the fruit ; 

 that they have no albumen ; and that there is hardly 

 more difference between the calyx and corolla of the 

 one than of the other ; that is to say, that they are in 

 both cases very similar to each other in appearance ; 

 moreover, that in each tribe the stamens grow from 

 the sides of the calyx-tube, and the ovary is inferior. 

 These resemblances are sufficient to show that the two 

 tribes are allied to each other in no very distant degree, 

 although they do not prove them to stand in imme- 

 diate contact. But I have not asserted that such was 

 the case ; in fact, the most direct affinity of the 

 Gourd is perhaps with the Passion-flower Tribe, as has 

 been stated on a former occasion (Vol. I. p. 710* 

 From those plants, however, the Gourd Tribe deviates 

 in many important particulars, so that, in reality, 

 there is no known natural assemblage that they im- 

 mediately impinge upon. 



EXPLANATION OF PLATE XXX. 



L The Cactus Tribe. — 1. A flower of Cereus speciosus, the na- 

 tural size ; a a the bracts ; b the ovary. — 2. The stamens, magnified, 

 with a portion of the tube of the flower at a ; 6 the filaments ; c the 

 starry stigma. — 3. An anther, with a portion of a filament adhering to 

 it. — 4. A section of a part of the tube of a flower, with the ovary at a, 



