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Linn. Transact. vol. 16 p 685. R. Brown "on the organs & mode of fecund. in Orchid & Asclep" other subjects

For nearly a century disputes concerning mode of impreg in Orchidiae; in 1764 from Linnaeus to present time, doubt have been entertained whether influence of pollen might not be communicated internally - caution from cryptogamic Plants.

p 689 "male influence or principle of arrangement, as it is termed by John Hunter"

p 704 Brown's sole difficulty in believing that actual contact of pollen necessary in Orchidiæ, arose from fact that in Europe & Tropics every observer has seen "that all the capsules of a dense spike are not unfrequently ripened" which seems hardly reconcilable with impregnation by insects. (in note observes same difficulty applies to dense spikes of Coniferæ, Zamia & Zea) remarks that he has actually found in Orchidiæ that pollen by some means had been applied to the stigma "takes at many different heights in the Spike"

p 708 in Orchideae that pollen may "be excited by the stigma of another (species) belonging to a very different tribe"

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p. 717 C. K. Sprengel in 1793 considers insects necessary for impreg. of Asclep & considers that extraordinary activity of insects is produced by intoxicating secretion of nectariæ. Brown adds form of inflorescence favourable to Bees crawling from flower to flower (rather hostile to intermarriage)

718 in Asclepias, pollen-masses in early stages of flower are absolutely distinct from glands & processes of stigma - (These latter apparently additional parts greater distinctive character in Asclep. & Orchidiæ.)

p. 726. Mr. B. has examined 7 spec. of Asclepias & same essential structures in each - seems to have often found pollen masses moved by insects

p.727 Could perceive no secretion on part of stigma in Asclep. where pollen tubes enter, [note] any difference in texture on that side of pollen-mass which is increasingly ruptured (says no doubt there must be some difference in both). This latter side is on the inner side, with respect to pollen-case, which shows how absolutely necessary it is that pollen-mass should be pulled out of case.

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So that this great anomaly does not exist in foetal state of flower

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p 728 applying pollen of one spec. of Asclep to stigma of other the usual changes generally took place in grain but slower - However pollen-mass of A. purpurascens applied to Epipactis palustris change took place sooner ie within 24 hours

p 730 in Hoya carnosa B. has not been able to place pollen-masses on stigma in such manner that tubes have been protruded into it - nor can conjecture how this is effected. The pollen-masses of this plant burst on inner side. (A woodcut might be given of pollen-masses & Glands & stigma with one adhering of Asclepias)

p 731. In impregnation of Orchidiae; agency of insects very frequently employed, though from position of organs not necessary in all - but in those Ascelipiadae, which have been carefully examined "the absolute necessity for this assistance is manifest"

In both these families the pollen-mass is removed by the gland adhering firmly to pollen-mass & less firmly to or point of attachment stigma, than to insect

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739 in Orchidiæ in Bonatea speciosa. B. has succeeded with one pollen-mass impregnating most of flower in one spike for insects to do this (& hence intermarriage probable) it only requires that adhesion of gland to insects should exceed that of pollen-mass to stigma & the adhesion to the latter to be be greater than that of separate grains together. Believes this is case with greater number of Ophrydeæ & in many of Neotteæ & Arethusæ - but genus Ophrys itself offers exception to this law of adhesion (in which flower stigma is protected by concave processes) and here impregnation can be effected without agency of insects & generally whole pollen mass is found adhering to stigma - Hence explains similitudes of these) flower to insects to keep them away - Experimentise on Bees - how do they find flower – [illeg] they around dead Bee with honey &c &c

Examine British Ophys - do Bees frequent them? Fact explicable without Browns hypothesis if whole pollen mass desirable for impregnation???