MR. M. T. MASTERS ON AXILLARY PROLIFICATION IN FLOWERS. 483 



Pully three-fourths of the entire number of genera recorded as occasionally the subjects 

 of this irregularity possess in their usual state some peculiarity of the thalamus ; for 

 instance, in about a third of the whole number of genera, the thalamus is more or less 

 prolonged between some or other of the floral whorls, e. g., Caryophyllacem, Fotentilla, 

 Anemone, Dictamnus, Umbelliferce, &c. About one-fourth of the genera have numerous 

 stamens or numerous carpels, or both, springing naturally from the thalamus. In others 

 (about one-sixth) the thalamus is enlarged into a disk, or else presents one or more glan- 

 dular swellings, e. g., Beseda, NymphcBa, Cruciferce. In the last-named family, as has 

 been already remarked, prolification is very common. It would be interesting to ascer- 

 tain precisely what part of an inflorescence is most liable to this affection ; but as in- 

 formation on this point is but rarely given in the records of these cases, I can only give 

 the results of my own observations, which go to show that, in a many-flowered inflo- 

 rescence, those flowers at the outside, or at the lower portion, seem to be more frequently 

 the subjects of this change than those situated elsewhere. This may probably be 

 accounted for by the fact that the malformation is met with most generally in plants 

 with an indefinite form of inflorescence, and therefore the lowermost or outermost flowers 

 are most fuUy developed ; the upper flowers being in a less advanced condition, the 

 change is more likely to be overlooked in them ; or it may be that, from the unusual 

 luxuriance in the lower flowers, the upper ones may be either present in their ordinary 

 condition, or may be (as indeed frequently happens) stunted in the size and proportion 

 of their several parts. 



Various changes in the form or arrangement of the several floral whorls accompany 

 this malformation ; some of these affect the particular organ or organs implicated, and 

 these only, while in other cases some other parts of the flower likewise undergo mo- 

 dification. The changes most commonly met with are such as may be classed under 

 Goethe's theory of retrograde metamorphosis : for instance, if a supplementary bud 

 be developed in the axil of a sepal, that sepal is likely to be more than ordinarily leaf- 

 like in appearance. The dislocation of the affected sepal from its fellows is a very fre- 

 quent occurrence ; in cases of this kind the detached sepal is placed below the others, 

 thus approximating, in position as well as in function, to the bracts. In some of the 

 instances of proliferous pears, on which I shall have occasion to comment, the sepals 

 are described as sharing in the succulent character of the fruit. 



The petals, under such circumstances, often exist in the guise of sepals or of small 

 leaves ; and instances are recorded wherein the place of the calyx and corolla was sup- 

 plied by a succession of overlapping green scales, from the axils of which the new buds 

 arose. Such instances seem to afford an extreme degree of a more common change, 

 viz., the diminished size and contracted appearance of the sepals and petals when 

 affected with axillary prolification. They have also a close relationship to such develop- 

 ments as we see in the Wheat-ear Carnation, in certain species of the genus Ifasa and 

 others, wherein the calyx is repeated over and again, to the partial or complete sup- 

 pression of the other parts of the flower. All these cases may be in part explained 

 by the operation of the principle of compensation. 



When the androecium is affected, the stamen either remains unaltered, or is present 



