Linncean Socielii. "71 



gpeciosa, aS ti^elMis'if* the other Orckidece examined with this view, 

 that the earliest appearance of these tubes is in the tissue of the 

 stigma in the immediate neighbourhood of the pollen tubes, from 

 which they are with difficulty distinguishable, and only by their 

 generally more flattened and less granular appearance, and by those 

 interruptions in their supposed cavity which he had formerly ob- 

 served, and termed coagula; — that from this part of the tissue they 

 gradually descend, at the same time increasing apparently both in 

 number and length, until they arrive in the cavity of the ovarium, 

 where the cords which they form also by degrees elongate and sub- 

 divide in the manner described in the original paper. In addition 

 to the account there given, he observes that although in several 

 cases he has not been able to trace any tubes going off from the 

 six principal cords, yet that in others, and particularly in Orchis 

 Morio, he has seen them scattered over the whole surface of the 

 placentse; and in the same species, in several, though not in many 

 instances, he has been able to trace a single tube to the aperture of 

 the testa of an ovulura. Since this paper was read, the author has 

 found in Habenariaviridis, in like manner, and in many cases, tubes 

 inserted into the apertures of ovula. 



To account for the greater part of the flowers of an Orchideous 

 spike being fecundated, which not unfrequently happens, he ob- 

 serves that from the greater degree of viscidity existing in the re- 

 tinaculum than in the stigma, and from the viscidity of the sur- 

 face of this organ being sufficient to overcome the mutual cohe- 

 sion of the lobules of pollen in most Ophrydece, a single insect may 

 readily impregnate many flowers with one and the same mass of 

 pollen ; a fact which he has confirmed by experiment in Bonatea. 

 He observes, however, that even in Ophrydece exceptions occur 

 to these relative degrees of viscidity, especially in Ophrys, the 

 insect forms of whose flowers are so striking; and as he finds, that 

 in this genus the assistance of insects in impregnation is less ne- 

 cessary, he concludes that these forms are intended rather to repel 

 than attract, and he adds that the flowers of Orchidece having those 

 remarkable forms, resemble the insects of the country in which the 

 plants are found. 



And lastly, he remarks, that in a few cases, from the relative po- 

 sition of the parts of the flower, the pollen-masses are brought into 

 contact with the secreting surface of the lateral stigmata, and the 

 assistance of insects is therefore wholly superseded, as in Neottia 

 e/ata, which, accordingly, seldom fails uniformly to ripen its cap- 

 sules. 



The East India Company have presented to the Linnaian So- 

 ciety their magnificent Herbarium, containing the plants collected 

 between long. 73" to ll-t° E. and lat. ^2° N. to the equator, by 

 Kcinig, Roxburgh, Ruttler, Russell, Klein, Hamilton, Heyne, 

 Wight, Finlayson, and Wallich. It includes about 1300 genera, more 

 than 8000 species, and amounts, in duplicates, to at least 70,000 

 •pecimens, — the labours of half a century. 



