Miscellaneous. 365 



MISCELLANEOUS. 



8PADIX PURPUREA, GOSSE. 



To the Editors of the AnnaU of Natural History. 



Falmouth, September 30, 1853. 

 Gentlemen, — The Spadix purpurea, Gosse {Arum Cocksii, 

 Vigur3; vide Report of the Royal Polytechnic Society, 1849) is an 

 old friend of mine, having found it in the autumn of 1844, attached 

 to the under surface of a large stone, extreme low water mark, spring 

 tide, Gwyllyn-vase, in the neighbourhood. Since that period a great 

 number of specimens have been sent to some of the first-class natu- 

 ralists of the age, in this country, on the continent, and in America, 

 but hitherto it has proved an enigma not easily solved. In the year 

 1847 Mr. J. Alder sent several from Falmouth to the Members of 

 the Natural-History Section, British Association, and specimens alive 

 were forwarded, per post, to Sir G. Dalyell, but unfortunately death 

 terminated the career of this good and great man before he had time 

 to untie the Gordian knot. I am glad that another habitat has been 

 found for this interesting creature. I have repeatedly produced the 

 young from the ova ; they are free for several days, and perambulate 

 on their stilt-like legs with ease and agihty. 



I am, Gentlemen, your obedient servant, 



W. P. Cocks. 



Note on the Parasitism of Comandra umbellata, Nutt. 

 By Asa Gray. 



So long ago as the year 1847, Mr. William Mitten, an English 

 botanist, communicated to Hooker's London Journal of Botany 

 (vol. vi. p. 146. pi. 4) a brief article, on the ceconomy of the roots 

 of Thesium linophyUum ; in which he shows that the roots of this 

 plant are parasitic ; the ramifications of the root forming attachments, 

 by means of suckers, with the roots of adjacent plants of various 

 species. The same parasitism probably occurs in other species of 

 Thesium, if not in the genus generally. But I am not aware that 

 the fact has been confirmed on the continental species, which are 

 somewhat numerous, although attention has been called to the sub- 

 ject by the reprint of Mr. Mitten's article in the ' Annales des Sciences 

 Naturelles' (in the volume which bears the nominal date of 1847), 

 and an interesting extension was at once given to the discovery by 

 M. Decaisne, who detected a similar parasitic attachment of the 

 rootlets oi Meiampyrvm, Pedicularis, and other rhinanthaceous plants 

 long known to be uncukivable. 



In the Botanical Text-book, I had called attention to the related 

 genus Comandra, which replaces Thesium in this country, as likely 

 to exhibit the same parasitic ceconomy, but, pressed by other occupa- 

 tions, had neglected to make the examination myself ; nor had I anv 

 notice of the observation having been made by others, although 

 Comandra nnthpllata i$ everywhere a common plant in the United 

 States. 



