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SEXUAL FORMS OF CATASETU&T. 



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It remained for Darwin to investigate the structure of the 

 flowers, and to show by what remarkable mechanisms the work 

 of fertilization was accomplished. In the case of the male and 

 female flowers, the conclusions arrived at are thoroughly satis- 

 factory ; but the same cannot be said respecting the so-called 

 hermaphrodite form. Of this he observes, after describing the 

 floral envelopes : — " The antennae are not so long as in the male 

 C. tridentatum, and they project symmetrically on each side of 

 the horn-like projection at the base of the labellum, with their 

 tips (which are not roughened with papillae as in the male flower) 

 almost entering the medial cavity. The stigmatic chamber is of 

 nearly intermediate size between that of the male and female 

 forms ; it is lined with utriculi charged with brown matter. The 

 straight and well-furrowed ovarium is nearly twice as long as in 

 Monachanthus, but is not so thick where it joins the flower; 

 the ovules are not so numerous as in the female form, but are 

 opaque and pulpy after having been kept in spirits, and resemble 

 them in all respects. I believe, but dare not speak positively as 

 in the case of the Monachanthus, that I saw the nucleus projecting 

 from the testa. The pollinia are about a quarter of the size of 

 those of the male Catasetum, but have a perfectly well-developed 

 disc and pedicel. The pollen-masses were lost in the specimens 

 examined by me ; but fortunately M. Eeiss has given, in the 

 1 Linnean Transactions,' a drawing of them, showing that they 

 are of due proportional size, and have the proper folded or cleft 

 structure ; so that there can hardly be a doubt that they are 

 functionally perfect"*. 



These results were obtained from a specimen preserved in 

 spirit, but during la*t autumn Mr. F. W. Moore, Curator of the 

 Glasnevin Botanic Garden, was good enough to send me a living 

 raceme of the same identical form. After careful examination I 

 can only say that the whole series of female organs are as imper- 

 fect as in any other male Catasetum, while, on the other hand, 

 the male organs themselves differ in no respect whatever from 

 those of several allied species. In other words, that the form in 

 question is a male only, and belonging to the group in which 

 Darwin showed that both the antennae are sensitive ; as opposed 



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to the other group (including C. trident at urn), in which one only 

 is sensitive, the other beinir turned round near the ba.se of the 





* Darwin, in Journ. Linn. Soc. vi. p. 156. 





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