40 



and in his extremity he appealed to professional skill for a remedy. Mr. Wood was not 

 long in ascertaining the cause of the trouble. A small magnifier revealed the fact that 

 the so-called fungus was nothing more than the sticky pollen of a certain milk-weed. He 

 wrote immediately to his correspondent stating his discovery, and told him to search the 

 country for several miles in his neighbourhood, and he would somewhere surely discover 

 a large tract of this mischievous Asclepias. In about a fortnight he received another 

 letter confirming his theory. The plant abounded in the locality. It had, therefore, 

 been cut down before the scythe, after which the trouble had ceased." 



If the modes of fertilisation of all plants deserve our attention, each flower having 

 its own mysteries to be solved, it is pre-eminently the case for Orchids. The flowers in 

 this order are shaped on a type so different from those of any other, that they seem to 

 belong to a world of their own. Their endless variety of form, to which are often added 

 the most exquisite colours, has always attracted notice \ but the interest in them has been 

 considerably enhanced by the discovery in these peculiar shapes, of wonderful and minute 

 contrivances to make use of the visits of insects for cross-fertilisation. 



Charles Darwin gave much attention to this subject, and published the result of his 

 researches in his admirable work " On the various contrivances by which British and 

 Foreign Orchids are fertilised by Insects, and on the good effects of Intercrossing." When 

 the first edition appeared in 1862, Prof. Asa Gray examined twenty-two American 

 Orchids, and wrote some valuable articles on the arrangement of the organs, and the mode 

 of fertilization of their flowers, (American Journal of Science and Arts, 1862, 1863). 

 But no visits of insects were then recorded by him, and, altogether, very few seem to have 

 been observed on North American Orchids. Prof. Gray mentions one insect visitor in 

 the last edition of his Botanical text book ; but Prof. S. I. Smith, of New Haven, Conn., 

 in the summer of 1863, was so fortunate as to see five species of insects on orchidaceous 

 flowers, or loaded with their pollen (Proceedings of the Boston Society of Natural 

 History, vol. ix, page 328). I cannot find any other instances recorded beside those six, 

 to which I shall add a few more. 



All that is known of the structure, habits, haunts, cultivation of the Orchids of New 

 England, has been summed up in a beautiful little volume*, by Mr. Henry Baldwin, who 

 well deserves the thanks of all lovers of Botany. To what is gleaned from former writers, 

 there are added the results of his own observations, as well as notes from other natural- 

 ists, and the work is most valuable for Canada, where the list of native Orchids is nearly 

 exactly the same as in New England. Mr. Baldwin treats of the different flowers in the 

 order of their dates of blossoming ; but I shall bring together the similar features and 

 characters by following the natural order of the genera according to Bentham and 

 Hooker's " Genera Plantarum."f 



These authors divide the order Orchids into five tribes : Epidendreae, Vandeae, 

 Keottieae, Ophrydeae, and Cypripedieae, of which the second only is unrepresented in the 

 Dominion. 



The flowers of the Cypripedieae have two fertile anthers, one on either side of the 

 column, and nearer its base than the three-lobed or rather three-fold stigma. Their pollen 

 forms on the anthers a viscid layer, which is detached and carried away by insects in 

 much the same way as the pollen of most flowers. The other tribes present great 

 differences in these respects. In the first place, their flowers possess only one anther, 

 which is situated at the extremity of the column. Then, their pollen is found in the 

 two cells of the anther, cohering in elongated masses, or pollinia, which are provided at 

 one end with a drop of viscid matter secreted by the rostellum, which is one of the three 

 stigmas transformed. The pollinia thus stick fast readily to whatever comes in contact 

 with the viscid end, and are by this means withdrawn from their cells. This arrange- 

 ment recalls that in the milk-weed mentioned before, though in that case, the pollinia 



*T1il> Orchids of New England. New York, 1884. J. W. Wiley & Sons. The book is illustrated with 

 40 figures, of which 15 are fine full-page plate*. One cannot help, however, finding fault with some figures. 

 Instead of representing the bold and straight lines in the plants, there has been sometimes an attempt to 

 improve upon nature by curving stalks and leaves in a painful distortion, painful at least to a botanist. 



V :. 111. London, 1883. 



