i862 1871] JOHN SCOTT 313 



(October, 1862) for quotation from M. Baillon on pollen- Letter 637 



tubes finding way from anthers to stigma in Helianthemum. 



I should doubt gum getting solid from [i.e. because of] 



continued secretion. Why not sprinkle fresh plaster of 



Paris and make impenetrable crust ? x You might modify 



experiment by making little hole in one lower corner, and 



see if tubes find it out. See in my future paper on Linum 



pollen and stigma recognising each other. If you will tell 



me that pollen smells the stigma I will try and believe you ; 



but I will not believe the Frenchman (I forget who) who 



says that stigma of Vanilla actually attracts mechanically, 



by some unknown force, the solid pollen-masses to it ! Read 



Asa Gray in 2nd Review of my Orchis book on pollen of 



Gymnadenia penetrating rostellum. I can, if you like, lend 



you these Reviews ; but they must be returned. R. Brown, 



I remember, says pollen-tubes separate from grains before the 



lower ends of tubes reach ovules. I saw, and was interested 



by, abstract of your Drosera 2 paper ; we have been at very 



much the same work. 



To J. Scott. Letter 638 



Down, Feb. i6th [1863]. 



Absence from home has prevented me from answering 

 you sooner. I should think that the capsule of Acropera had 

 better be left till it shows some signs of opening, as our object 

 is to judge whether the seeds are good ; but I should prefer 

 trusting to your better judgment. I am interested about the 

 Gongora, which I hope hereafter to try myself, as I have just 

 built a small hot-house. 



Asa Gray's observations on the rostellum of Gymnadenia 

 are very imperfect, yet worth looking at. Your case of 

 Imatophylluvi 3 is most interesting ; even if the sport does 

 not flower it will be worth my giving. I did not understand, 



1 The suggestion that the stigma should be covered with a crust of 

 plaster of Paris, pierced by a hole to allow the pollen-tubes to enter, 

 bears a resemblance to Miyoshi's experiments with germinating pollen 

 and fungal spores. See Pringsheinfs Jahrbucher, 1895; Flora, 1894. 



* A short note on the irritability of Drosera in the Trans. Bot. Soc. 

 Edin.,Vo\. VII. 



3 A sucker of Imatophyllum minatum threw up a shoot in which the 

 leaves were " two-ranked instead of four-ranked," and showed other 

 differences from the normal. Animals and Plants > Ed. II., Vol. I., p. 411. 



