721 



In continuation of this subject I now follow up tie quotation from 

 Lindley. 



" The genuine species of Helosis show on their rhizome roundish 

 conical buds seated on a very short stalk, or altogether sessile, inclos- 

 ing the rudiments of a future head within a very thin involucre, as a 

 fungus within the volva; this latter after a time splits into three or 

 more segments, and emits the flower-head enlarged and furnished 

 with a stalk, which is altogether naked except at the base, where it 

 is surrounded by the scale-like segments of the withering involucre. 

 This is the most simple form of involucre, which in the other genera 

 becomes more and more complicated, and finally runs into numerous 

 series of imbricated scales, which clothe the stipes more or less com- 

 pletely. In those genera which grow upon the bark of the stems of 

 trees, there are some diversities of structure in the organs of vegeta- 

 tion that are very remarkable. Blume tells us that Kafflesia Patraa 

 appears upon the creeping roots or stems of Cissus scariosa in the 

 form of solitary or clustered hemispherical dilatations, which look 

 like excrescences or expansions of the root. These excrescences are 

 something of the nature of leaf-buds, consisting of layers of scales 

 and a more solid centre. As the latter increase in size they burst 

 through the wrapper by tearing it irregularly from the apex towards 

 the base, and develope themselves in the form of numerous scales, at 

 first flesh-coloured, then brownish, and finally deep purple, which 

 surround the flowers. As soon as these parts are exposed, richly 

 nourished as they are by the humid air that surrounds them, they 

 grow with such rapidity, that it is reported that Rafilesia, which, 

 when full-blown, is a yard across, and when unexpanded is as large 

 as a middle-sized cabbage, only takes about three months for its 

 complete development." — X. V. K. 84. 



Remarks on the parasitism of the rhizogens might be indefinitely 

 multiplied ; I trust, however, that the above will sufficiently show 

 that their mode of growth in the various genera agrees in kind and 

 differs only in degree. I have not much doubt that this will be con- 

 firmed by further investigations and discoveries; and that conse- 

 quently a conclusive answer will be afforded to Mr. Griffith's 

 objection, that a diversity of characters has been *' sacrificed to an 

 appearance of parasitism on roots." 



His second objection, referring to the " assumed absence of any 

 ordinary form of vegetable embryo," need not detain us, since it is 

 more than probable that extended observation will detect the embryo 



