Chap. IX. SECEETION OF NECTAE. 265 



elaborate mechanism for the ejection and transportal 

 of the poUinia of Catasetum, with the sensitive ros- 

 tellum SQ wonderfully modified, with the sexes borne 

 on distinct plants, we may perhaps give the palm of 

 victory to this genus. 



SECEETION OF NECTAE. 



Many Orchids, both our native species and the 

 exotic kinds cultivated in our hothouses, secrete a 

 copious supply of nectar. I have found the horn-like 

 nectaries of Aerides filled with fluid ; and Mr. Eodgers, 

 of Sevenoaks, informs me that he has taken crystals 

 of sugar of considerable size from the nectary of A, 

 cornutum. The nectar-secreting organs of the Orchidese 

 present great diversities of structure and position in 

 the various genera ; but are almost always situated 

 towards the base of the labellum. In Disa, however, 

 the posterior sepal alone, and in Disperis the two 

 lateral sepals together with' the labellum, secrete 

 nectar. In Dendrobiwn chrysanihum the nectary 

 consists of a shallow saucer ; in Evelyna, of two large 

 united cellular balls ; and in Bolbophyllum cupreum, of 

 a medial furrow. In Cattleya the nectary penetrates 

 the ovarium. In Angrsecum sesquipedale it attains the 

 astonishing length of above eleven inches ; but I need 

 not enter on further details. The fact, however, 

 should be recalled, that in Coryanthes the nectar- 

 secreting glands pour forth an abundance of almost 

 pure water, which drips into a bucket formed by the 

 distal part of the labellum ; and this secretion serves 

 to prevent the bees which come to gnaw the surface of 

 the labellum from flying away, and thus compels them 

 to crawl out through the proper passage. 



Although the secretion of nectar is of the highest 



