1886. ] PROF. F. J. BELL ON BIPALIUM KEWENSE. 167 
assigned to the genus Bipalium’. The only writer who seems to 
have remarked the variability in the form of the head is M. Hum- 
bert, who figures* the head of Bipalium diana, as living and when 
it is greatly contracted ; the differences are, however, quite slight as 
compared with those in the figures now given (Plate XVIII.). More- 
over, M. Humbert continues to use the form of the head as a distinctive 
character, and seems to have only incompletely appreciated the moral 
of what he saw. Referring to the paper of Prof. Perceval Wright, 
M. Humbert says:—‘Il donne une figure .... qui représente 
Pextrémité antérieure semilunaire et a du evidemment étre faite 
daprés un individu conservé dans l’alcool, tandis que celle de la 
D. grayia a été dessinée d’aprés le vivant. C’est sans doute 4 ces 
deux maniéres d’observer, encore plus qu’A des particularités 
spécifiques qu’il faut attribuer les différences profondes que l’on 
remarque dans la forme des extrémités antérieures de ces deux 
espéces.”” But the differences shown in Prof. Wright’s woodcuts 
of the two species are not as “ profound” as those seen in the 
figures of the single living specimen here reproduced. So that, 
though M. Humbert recognized the difference between living heads 
and heads preserved in spirit, he does not seem to have recognized 
what is much more important—that the form of the head varies 
constantly during life. 
Ifa Planarian in a torpid condition (Pl. XVIII. fig. I) be then and 
there seized and put into spirit, it will be found, no doubt, to have an 
obtusely blunted head, hardly wider than the body*; on the other hand, 
some, at any rate, if killed while in full activity, will be found to have 
heads shaped like a cheese- cutter or some modification thereof. 
Hab. Mr. Salvin has lately received orchids from 8. America and 
S. Mexico, and from Burmah ; but he has also had specimens from 
Kew Gardens, whence the originals came to Mr. Moseley. 
In 1883 Dr. Giinther received some specimens from Welbeck 
Abbey*, where they had been known for three or four years pre- 
viously ; Mr. Thiselton Dyer tells me that there is no history of any 
communication between the gardens at that place and Kew, and adds 
“‘ we have probably therefore been stocked from a common source.” 
A specimen found in a greenhouse in Clapham Park was sent to Dr. 
W. M. Ord, and is now in the possession of Prof. Ray Lankester ; 
the early history of this specimen is unknown. In the hope of being 
able to extend our knowledge of this worm, I have written a note to 
the editor of the ‘ Gardener’s Chronicle’ °, which may result in some 
further information, and perhaps in the discovery of fresh examples 
* The French translator of the latest authoritative work on General Zoology 
by converting “ Kopftheil durch Lappen-Vorsatze halbmondformig” into “ Région 
céphalique en croissant par la présence de deux appendices lobés,” shows that he 
too regards the lateral parts of the head as being constant in form and position; 
nevertheless they are not so. 
* Mém. Soc. Genéve, xvi. p. 303, figs. 1, 1a. 
* Fig. H in Plate XVIII. shows the form of the head in the specimen under 
description, now that it is dead and preserved in spirit. 
* See his letter in the ‘Gardener’s Chronicle,’ xix, (1883) p. 415. 
® Published on March 13th, 1886. 
