146 



HARDWICKE'S SCIENCE-GOSSIP. 



[July 1, 1870. 



I dare say Mr. Kitchener knows the little bit of 

 superstitious folk-lore that is attached thereto — 

 namely, that two people must eat the two kernels, 

 and wish ; and their wishes will be fulfilled. I have 

 growing at the present time two young oak-trees 

 that came out of one acorn; and the same thing 

 often happens, both with the oak and the horse- 

 chestnut. I described some time ago, in Science- 

 Gossip, a plant of Snapdragon of two colours, that 

 was, I have not the least doubt, produced from a 

 double embryo. If the embryos are separate in the 

 testa, two distinct plants will be produced — " ve- 

 getable twins," in fact; but if the embryos are 

 imperfect and united , together, then a monstrous 

 form, of the nature of " Siamese Twins," will be 

 the result. In this, as in so many other respects, 

 vegetables resemble animals in their economy. 

 Double -yolked eggs will produce two perfect 

 chickens, if the yolks are completely separate, and 

 both fertilized ; but if the yolks are joined together, 

 as is often the case, chickens with four legs or two 

 bodies, or otherwise unpleasantly united, are de- 

 veloped. This I have proved by experiment. 



It would be quite possible, therefore, for seeds 

 with three and four seed-leaves to have become 

 thus developed through a union of embryos, as 

 seems to have been the case with the examples of 

 Solanum and Haricot quoted by Balfour ; but I 

 am convinced that in all the examples I have lately 

 found, the extra leaf has arisen, not from this cause, 

 but from the splitting of one cotyledon into two ; 

 for, in addition to the three-leaved examples I have 

 enumerated, I have found a good many others, of 

 several species of plants, that exhibit this splitting 

 up in various stages ; some where the division has 

 only taken place near the apex of the leaf; others, 

 where it has extended so nearly to the base that the 

 cotyledon, at first sight, has all the appearance of 

 two perfect leaves, and only upon close inspection 

 is it found to be a single leaf, deeply cloven. The 

 series is completed by examples in which the coty- 

 ledons are quite distinct and equidistant, forming a 

 whorl around the plumule. 



Erom these observations, and from the similar 

 ones recorded by Mr. Paxton in the June number, 

 I am led to believe that in nine cases out of ten 

 triple cotyledons will be found to arise from chorisis. 

 The fact of the resulting leaves being perfect in 

 shape, and of the ordinary size, is no argument 

 against this ; for in the examples that I have met 

 with, the new leaves formed were of the usual size 

 and shape, even when the separation was not qtiite 

 complete. 



Still, it seems to me quite possible that in some 

 cases three-leaved embryos may have grown from 

 tril'oliar phytons, as suggested by Mr. Kitchener ; 

 and that these variations may have been induced by 

 cultivation, which we know plays strange pranks 

 with vegetable organisms. Certainly, the tricots 



ledonous seeds that I have found have, with one 

 exception, been those of cultivated plants ; and 

 even that exception, the Ranunculus, was growing 

 in a pot in a hotbed. Sycamores, however, which 

 have yielded the greatest number of curious forms 

 both to Mr. Paxton and myself, could scarcely be 

 said to be in a cultivated condition. I have not 

 sought in the fields or hedge-banks for examples, 

 because the garden was the most handy place ; but 

 I think variations would most likely be found 

 amongst the seedlings of wild plants, if we were to 

 look for them. 



Whilst examining the radishes, I found some very 

 curious examples of leaves, intermediate between 

 cotyledons and " rough leaves." There are many 

 plants which the cotyledons resemble, in a slight 

 degree, the second leaves — as, for instance, Es- 

 choltzia and Feverfew, and in these there is a regular 

 gradation from the slightly-cut cotyledons to the 

 deeply-cut and jagged upper leaves. But in the 

 radish there is so wide a difference of form and 

 texture between the obcordate, smooth seed-leaves, 

 and the lyrate and very rough rough-leaves, that an 

 intermediate leaf, partaking of both their charac- 

 ters, becomes more remarkable. I have often seen 

 them, and have found examples where one half of 

 the intermediate leaf resembled a cotyledon, and 

 the other half an ordinary leaf ; again, where it re- 

 sembled an elongated cotyledon, with a tendency to 

 roughness. These are not third cotyledons deve- 

 loped as in other cases. There is always this dif- 

 ference between cotyledons and other leaves, that, 

 whether a plant bears opposite or alternate leaves 

 on its stem, the cotyledons are always opposite, 

 forming a sort of socket from which the plumule 

 springs ; but in the other tricotyledonous plants, 

 and doubtless also in those found by Mr. Kitchener, 

 the third cotyledon was in the same plane as the 

 other two. But these leaves of the radish are per- 

 fectly different, for they are not placed in the same 

 plane as the true cotyledons, but are part of the 

 plumule ; they are, both in form and in position, 

 intermediate ; and I think they show us that cotyle- 

 dons are not organs per se, but are simply the two 

 lowest leaves of the stem, altered for a special 

 purpose. 



MUSICAL EISH. 



THE communication from my old friend, the Rev. 

 W. W. Spicer, under the head of " Musical 

 Fish," which I have just read in the March number 

 of Science-Gossip, has put me in mind of an in- 

 tention long entertained, but never as yet fulfilled, 

 of sending you an account of a phenomenon similar 

 to the one described by him, which I witnessed some 

 years ago. 



In the month of February, 1857, having waited 

 at Tavoy a long time in vain for the arrival of the 



