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OBSERVATIONS UPON MULING AMONG PLANTS. 



quite useless except accompanied by rare qualities of tact, order, 

 neatness, perfect fairness and freedom from prejudice, unwearied 

 watchfulness, and accurate judgment. The immense variety of 

 objects which demand attention, not one of which, if any trust- 

 worthy inductions are to be made, must ever be lost sight of, the 

 length of time which is required even for the simplest results, the 

 careful labelling of every plant, and registering of the phenomena 

 as they arise, the precision with which every capsule must be 

 examined, and every seed numbered, the difficulty of preventing 

 confusion amongst some thousands of seedlings, the necessity of 

 growing every plant in a separate pot, and after all the labour 

 of generalising so many observations, are enough to deter any 

 ordinary person at a very early stage of the investigation. Our 

 author exhibits all the qualities enumerated, as far as we can 

 judge, in a very eminent degree ; and the consequence is that he 

 has produced a work which from first to last secures the faith 

 of the reader. 



As there is little probability from its size that it should be 

 made accessible to the English student, except indeed the Ray 

 Society or some other similarly constituted body should take it 

 in hand, we think that it may be useful to give an analysis of the 

 more interesting and important part of its contents; and though, 

 as remarked above, we cannot look for much novelty, it may not 

 be wholly useless to lay before our readers, in a connected series, 

 the principal facts which it details, omitting for the most part all 

 that is merely historical. 



The author commences with some general observations on 

 hybrid fecundation, confining the notion of a hybrid, whether in 

 the animal or vegetable kingdom, to beings produced by hetero- 

 geneous fecundation, and by no means including mere casual 

 degenerations or deviations, whether arising from grafting or 

 other causes. That such fecundation is not the normal course 

 of nature, but the effect of force and circumstance, is clear from 

 the very rare occurrence of hybrids, generally speaking, in nature, 

 and the small extent in which muling is practicable, even in 

 cases where very close external resemblance would seem to make 

 it probable ; a fact which shows clearly that it depends upon pecu- 

 liar inward constitution, and which may therefore become matter 

 of experience, but, like so many other subtle mysteries of nature, 

 can never be expected to be ascertained beforehand by direct 

 observation. Not only must the pollen of the hybridizing plant 

 be in perfection precisely at the moment when the tissue of the 

 stigma is in a fit state for its reception and the proper success of 

 its functions, but even where the access of its own pollen is per- 

 fectly debarred from the stigma of a plant, the success of hybrid 

 fecundation seems from experiment to require a more delicate 

 and precarious adjustment of every favourable condition — to be 



