OUAP. Vn. CATASETUM TEIDENTATUM. 197 



he was surprised at the gigantic seed-vessels of the 

 Monachanthus ; and he correctly remarks that " here 

 we have traces of sexual difference in Orchideous 

 flowers." Dr. Criiger also informs me that in Trinidad 

 he never saw capsules naturally produced by the 

 flowers of this Catasetum ; * nor when they were fer- 

 tilised by him with their own pollen, as was done 

 repeatedly. On the other hand, when he fertilised 

 the flowers of the Monachanthus viridis with pollen 

 from the Catasetum, the operation never failed. The 

 Monachanthus also commonly produces fruit in a state 

 of nature. 



From what I had myself observed, I was led to 

 examine carefully the female organs of C. tridentatum, 

 callosum, and saocatum. In no case was the stigmatic 

 surface viscid, as it is in all other Orchids (except as 

 we shall hereafter see in Cypripedium), and as is 

 indispensable for securing the pollen-masses by the 

 rupture of the caudicles. I carefully looked to this 

 point both in young and old flowers of C. tridentatum. 

 "When the surface of the stigmatic chamber and of the 

 stigmatic canal of the above-named three species is 

 scraped off, after having been kept in spirits, it is found 

 to be composed of utriculi (including nuclei of the 

 proper shape), but not nearly so numerous as with 

 ordinary Orchids. The utriculi cohere more together 



* Dr. Hanoe writes to me that often occurred. J. G-. Beer says 



he has in his collection a plant of (quoted by Irmisch, ' Beitrage zu 



Catasetum tridentatv/m from the Biologie der Orchideen,' 1853, p. 



West Indies bearing a fine capsule; 22) that during three years he 



but it does not appear to have tried in vain to fertilise Catasetum, 



been ascertained that this par- but on one occasion, by placing 



ticular flower was that of Cata- only the viscid disc of a pollinium 



setum, and there is no great im- within the stigma, a ripe fruit 



probability in a single flower of was produced ; but it may be 



Monachanthus being produced by asked. Did the seeds contain 



a plant of Catasetum, as well as a embryos ? 

 whole scape, which we know has 



