MR. M. T. MASTERS ON PROLIFICATION IN FLOWERS. 361 



the axis within the carpels * ; in Thesium also, another genus with free central placenta, 

 this malformation has heen found. 



So also among plants with indefinite inflorescence, prolification seems very frequently 

 to afi'ect those wherein the axis is normally prolonged ; thus it is common in Dictamnus, 

 which plant has an internode supporting the pistil ; it is common among JJmhellifercB, 

 where the carpophore may be truly considered an axile production ; it is common among 

 BosacecB and Banimculacece, in many of which the axis or thalamus is well-marked, and 

 it is by no means infrequent in the flowers of the Orange, where the floral internodes are 

 also slightly elongated ; on the other hand, I have never observed the change, or heard of 

 it, in GeraniacecB, IlagnoUacece, and some other orders where the floral part of the axis is 

 at some point or other elongated; still there can be but little doubt that there is a real 

 relation between prolification and the normal extension of the floral internodesc 



Under these circumstances, those instances wherein the parts of the flower become 

 separated one from the other by the elongation of the internodes, would constitute a 

 lesser degree of the same change, which operates most completely in the formation of 

 a new bud at the extremity of the prolonged axis. Some specimens of Geum rivcde 

 (a plant very liable to become prolified) in my possession show this very clearly. 

 In the wild plant the thalamus is elevated on a short, stalk ; in the abnormal ones 

 the thalamus is simply upon a longer stalk than usual, or in a more advanced stage 

 of the deviation the lengthened thalamus takes the form of a branch provided with 

 leaves and terminated by a flower ; it is noticeable, also, in these specimens, that the 

 sepals of the lower flower have assumed entirely the dimensions and appearance of 

 leaves (sketch 1). 



Inasmuch as the pistil of the lower flower is frequently absent, and its place supplied 

 by the new flower-bud, it was suggested that the pistils were converted into the new bud ; 

 but, as Moquin well remarks, there is little ground for such an opinion, as the carpels are 

 frequently present, either quite unchanged or varioiisly modified. 



A singular instance of prolification in the central flower of one of the verticillasters of 

 Phlomis fruticosa fell under my own notice ; it was a case wherein the calyx was torn on 

 one side and one of its lobes had become petaloid. Between the calyx and the corolla were 

 three or four spathulate, hairy, bract-like organs ; the corolla and stamens were unchanged ; 

 but in place of the usual four-lobed ovary there was a single carpel with a basilar style, 

 terminated by a forked stigma. Occupying the place of the other lobes of the pistil was 

 an oblong woolly flower-bud consisting of calyx, corolla, and stamens, but with no trace of 

 pistn. I have been unable to find recorded any instance of malformation among Labiates 

 or Borages at all similar to this. It differed from most other examples of prolification in 

 that the axis was not prolonged, the adventitious bud occupying precisely the position of 

 the three lobes of the ovary that were absent. The sole remaining carpel had a style and 

 a stigma as perfect in appearance as though the pistil had been perfect (sketch 2). 



Prolification has occasionally been recorded in flowers that have, in their ordinary con- 

 dition, but one carpel, as in Leguminosce and in Scmtalacece. In LeguminoscB it would 



* Duchartre, Anu, des Sc. Nat. 3me serie, vol. ii. 1844, p. 293. 



3c2 



