43S Linncean Society. 



all cases, in communication with the stigma. The stigma he describes 

 as a glutinous disk, from which a central cord of the same nature is 

 continued through the style to the ovarium, where it divides into three 

 branches, each of which divides into two, the six branches so formed 

 running down, one on each side of the corresponding placenta to the 

 base, giving off rairiuli, which go to the ovula and separate them into 

 groups. A communication is thus, in his opinion, established be- 

 tween the anthera and ovula, which he supposed were impregnated 

 by an aura seminalis through their surface, and not, as he believes 

 to take place in other families, through the funiculus. 



In the spring of this year Mr. Brown renewed his observations on 

 this family, and the results of his investigations are very curious and 

 important. His attention was first directed to the relation which the 

 lateral and generally rudimentary stamina bear to the other parts of the 

 flower; and fully satisfied himself, that the opinion which he had ex- 

 pressed in his observations upon Aposlasia was correct, viz. that they 

 are placed opposite to the two lateral divisions of the inner series of 

 the perianthium, and not, as had been before supposed, to the lateral 

 divisions of its outer series. He then turned his attention to the 

 composition of the stigma with respect to tlie relation which its lobes 

 bear to the other parts of the flower and to the component parts of 

 the ovarium. He satisfied himself that Orcludece have in reality three 

 stigmata more or less confluent in general, but in some cases distinct, 

 and even furnished with styles of some length. • These stigmata are 

 opposite to the three outer divisions of the perianthium, and conse- 

 quently terminate the axes of the component parts of the ovarium, 

 which he regards as composed of three simple ovaria united by their 

 ovuliferous margins, — a structure in which the ordinary relation of 

 stigmata to placentae is that here found. 



In Cypripedium and Apostasia, in which the lateral stamina are 

 perfect, and the middle one without anthera, all the lobes of the 

 stigma are equally developed and of nearly similar form and texture, 

 and, as Mr. Brown has proved by experiment in Cypripedium, are all 

 equally capable of performing the function of the organ. But in 

 most cases, that lobe which is opposite to the middle and perfect 

 stamen and deriving its vessels from the same cord, does not perform 

 the function of the organ, there being hardly an instance of a per- 

 fectly developed stamen and stigma placed opposite to each other, 

 and having the same vascular supply. To this lobe the glands al- 

 ways belong, to which the pollen masses become attached, but from 

 which they are always originally distinct. Its office, therefore, is essen- 

 tially different from the lateral lobes, which are always present, more 

 or less developed, and capable of performing their proper office. 

 These lateral lobes are most developed in Satyrincs or Opiirydece, 

 especially in Bonatea speciosa, in which they have been mistaken for 

 portions of the labellum. That they are, however, actually the effi- 

 cient stigmata Mr. Brown has proved by experiment, in applying the 

 pollen mass to their secreting surface, which was followed by the en- 

 largement of the ovarium. In the ordinary structure, therefore, of 

 OrchidecE, in which only one perfect stamen is produced, the corre- 

 sponding 



