From John Scott 19 March 1864
March 19th. 1864.
I am surprised to find that your note of the 10th. ult. addressed to the Bot. Gar. has been returned to you,1 as I left my address with Mr. Mc.Nab…2 I am much obliged for your forwarding address to Mr. Kippist,3 I had quite neglected doing so. I had a note from Mr. Kippist sometime ago acknowledging receipt of missing portion of my M.S.4
I am gratified to find that my Primula paper is ordered for the Journal,5 afraid, however, of harsh critic〈isms〉 upon its many defects. I would have liked much Dr Hooker 〈to have〉 looked over M.S. before it had g〈one to〉 the printers.6 〈two or three words missing〉 made it more read〈able〉 〈 〉 now 〈several words missing〉〈 〉wing out of 〈several words missing〉
I am glad to hear of corrob〈orating〉 results fr〈om〉 experiments, respecting the correctness 〈 〉 view on Catasetum.7 After the results of our exp〈erime〉nts on Acropera—considering the relative conditions of ovaria—I candidly speaking had doubts as to the absolute sterility of the Catasetum.8 If I am right however, in the following analogy, and the case been otherwise, viz, Catasetum susceptible to imperfect fertilisation, it would not have mattered much. In fact it would have afforded a more complete accordance between the phenomena of sterilisation by hybridity & these manifested in the graduated separation of the sexes. In the former cases we know that in general the sterilising effects are first manifested by the male organs (In a short paper which I have lately communicated to Bt. Soc. of Edin. on the Sexuality of the Higher Cryptogams as evidenced by the occurrence of hybrids I have mentioned the bigeneric hybrid known as Bryanthus erectus as a probable exception to this law),9 in the latter, or Catasetum case, we have an apparent analogy with the above in the rudimentary anthers of the Catasetum form, and the more perfectly developed placenta & ovules of the Monochanthus.10 Are you inclined to lay any stress on the above?11 perhaps I am quite wrong.
I am almost afraid to tamp〈er with〉 the Acropera cases: they are most perplexing:12 the natural method of fertilization is singularly so 〈several words missing〉 rather in line 〈several words missing〉 〈 〉fore the fir〈 〉 〈several words missing〉 〈f〉lower inas〈much〉 as I find the odd sepal freeing itself from 〈two words missing〉 from the base upwards; and cohereing with them 〈 〉 alone for sometimes several days previous to the expansion of the flower; so as to leave apertures in either side of the column sufficiently large for the bodily admission of the smaller insects, or a means of access for the larger. 13 We might indeed suspect from the strong aromatic odour diffused by these plants in our hothouses during the night that they will be specially attractive to moths and other night-flying insects. Before fertilization they seem to offer no other attractions to insect visits, as I, like you have failed to detect a single drop of nectar;14 after fertilization, however, I find that in the Acropera Loddigesii and likewise the Gongoras atropurpurea and truncata an abundance of nectar exudes from the front of the column. This continues to be secreted even after the perianthal parts are entirely faded.15 (Have you observed this? I do not remember having observed it in any of the other genera of orchid on which I have experimented.) It is difficult to understand the meaning or use of this after-secretion of nectar, unless, indeed it be a provision in view of the difficulties attending effective fertilization: an in〈ducem〉ent f〈or〉 insects to continue their visits, and 〈 〉 〈obje〉ct of their search be not obtain〈ed〉 until 〈 〉 〈req〉uirements of the pl〈 〉 〈several words missing〉 make an estimate of 〈three or four words missing〉 produced by the different m〈ethods〉 by which I 〈have〉 succeeded in fertilizing the Acropera 〈 〉. Th〈ere〉 is manifestly a decreased fertility by 〈cutt〉ing off of the upper portion of column. By merely cutting off the clinandrum, however, I have nearly as fine looking capsules as those resulting either from the forcing in of the pollen-mass into the uncut stigmatic chamber; or by the immersing of them—pollinia—in viscous matter from other Orchids and applying them to stigmatic mouth.16 By the latter mode however, there is a very high per-centage of failures in the setting of the capsules; though in one or two of them thus produced are fine & plump… It is somewhat remarkable that the Gongoras should exhibit phenomena similar in every essential respect to those of Acropera!— I fear we will never fully understand these phenomena until we have opportunities of studying them in plants in their native habitats.17 I have a longing to be amongst them there.
I should have liked better if—health and time permitting—you had drawn up a paper on the above subject, and I would send notes with results of my experiments on A. Loddigesii & G. atropurpurea & truncata; so that with your own observations & experiments you 〈m〉igh〈t then〉 be enabled to give a most interesting paper.18 〈two or three words missing〉 however, that you would rather not 〈 〉 in the work. I will as you have desired myself 〈three or four words missing〉 possibly insert it 〈 〉 〈jo〉urnal of B〈otany〉 〈 〉 have now no jour〈nal〉 〈 〉 which I cou〈ld〉 communicate it. The Edin. N〈ew Phil.〉 Journ. 〈is a〉 〈com〉plete failure. The April No. is its last & as for 〈the〉 Trans. Bot. Soc Edin. it would not then be seen for nine or ten months.—19 I suppose you will be communicating Dr Crügers paper to the Linn. Soc. immediately in the case of my drawing up paper on Acropera might I notice his results—so far as relating to fertility of forms—as showing more forcibly the anomalous results of Acropera?20 I am busy drawing up tables of results of experiments of Peloric Antirrhinum Passifloras & Verbascums. Would your rather have me draw up independent papers on these? They were all undertaken at your suggestion, and now they are entirely at your service.21 If time had permitted you would indeed ere this have had them all. I will soon however have them prepared now.
I regret to find that you are still so weak; I trust you will improve as spring advances …
I am &c | J. Scott
On fertilisation of Gongora.
His work on peloric Antirrhinum, Passiflora, and Verbascum, done at CD’s suggestion, is at CD’s disposal.
Please cite as
Darwin Correspondence Project, “Letter no. 4432,” accessed on 31 July 2016, http://www.darwinproject.ac.uk/DCP-LETT-4432