492 MK. J. T. MOGGKIDGE ON PiCXALUDY 



modification (which can in no sense be called a malformation), it 

 is important to compare the structure in the normal and ab- 

 normal flower. In the normal lateral sepal (fig. 2 a) the limb is 



um 



more or lesd confluent with it, as in the case of the abnormal 

 sepals (fig. Ih); the central nerve has on either side of it two 

 bi- triiurcated nerves, the central and the lateral nerves springing 

 from tiie bundle of vessels which snpply the adjacent side of the 

 labelium, and form part of the group described by Mr. Darw'm 

 as the antero'hiteral \ but the central and posterior nerves jom 

 this bundle at a common point close to its immersion in the 

 ovary, while the anterior nerve unites with the same bundle of 

 vessels at a point nearer to the base of tlie labelium ; this ante- 

 rior nerve, in the abnormal flower, undergoes a complete change, 

 and, in place of being only once or twice branched, assumes in 

 every respect the character of the adjacent lateral nerve of the la- 

 belium, sending out a quantity of branched veins through the 

 newly developed lateral lobe and along its whole course on the 

 side away from the central nerve. Thus we have the following 

 important changes in either lateral sepal of these abnormal 

 flowers : — (1) the limb is confluent at one or more points with 

 the labelium ; (2) the anterior nerve takes on the character of 

 the much-branched adjacent nerve of the labelium ; (3) one of 

 the guiding-plates is developed ; (4) a lateral lobe and (5) a 

 hairy-surfaced structure, precisely similar to the corresponding 

 part of the labelium, replace the whole anterior longitudinal 



half 



form 



conception of the mode in which tendencies of any kind may be 

 transmitted through a lapse of time incalculably long either in 

 a dormant or active state. I have lately, during my attempts to 



arrange and draw deductions from a series of observations on 



minute variation in wild plants, become more and more impressed 

 with the belief that each individual includes within itself a great 

 variety of latent tendencies, the development of which is occa- 

 sionally facilitated by the disturbing action of changed surround- 

 ing conditions. Thus in Arlutus Unedo^ L., the fruits, when 

 suff'ering from the attacks of white scale, do not usually become 

 mere shapeless masses, but assume types well recognized as cha- 

 racterizing entire trees, and often present two or three forms on 

 the same branch, becoming ovate-acute, globose-depressed, sub- 



