TERATOLOGY IN MODERN BOTANY. 93 



frequently appeared in connection with several of the 

 flowers and resembled small foliage-leaves in form and 

 texture. Again, the doubling of the flowers occurred in 

 the most various ways, all intermediate stages between the 

 conversion of odd stamens and carpels into petals, and 

 complete doubling being represented, and some flowers 

 further had double, some treble corollas and calyces. And 

 besides this, fresh shoots were also observed in the interior 

 of some of the flowers. 



All these effects were produced by inoculation with a 

 parasite, a Phytoptus, which occurs in aborting buds of 

 Valeriana triptcris. The degree of metamorphosis was 

 not the same in all cases, but varied with the strength of 

 the infection, and with the sensitiveness of the plants. 



Two points in these experiments appear to me to be of 

 special significance. The one is the fact that, as in the 

 formation of galls, the malformations are due to a direct 

 action on the part of the parasite, and secondly, that in the 

 process there is no formation of new organs, but rather an 

 interference with any such formation. 



This statement may appear at first sight too sweeping, 

 wanting: in clearness, and doubtful, but I consider it as re- 

 presenting the correct position, and I will go on to support 

 it by some examples. When a flower becomes green the 

 foliage-leaves which supersede the petals, stamens, and so 

 on, take the form of the ordinary foliage-leaves of the plants, 

 e.g., in Drosera it is even found that the chloranthic blossoms 

 have upon their leaves the characteristic tentacles. The 

 chloranthy is, indeed, not always perfect, and the forms of 

 the leaves which result from it are then simpler, but the 

 extreme cases give very clear indications of the general 

 nature of the process. Moreover, when flowers become 

 double and new petals are formed, the latter have the 

 same form as the ordinary ones, in accordance with the 

 principle just laid down. The malformation consists in an 

 abnormal metamorphosis, and to a certain extent in pot 

 pourri of the various organs. But as in the development 

 of galls no histological components which are absent from 

 the plant make their appearance, so, in these malformations, 



