142 Mr Shipley, On the Occurrence of Bipalium [Feb. 9, 



an inherent regulating power to which Vochting has given the 

 name Rectipetality. But it is not certain that the klinostat does 

 remove external stimuli. Elfving's experiments on the growth of 

 grass-halms show that though the gravitation-stimulus is sym- 

 metrically distributed, it is not destroyed. If the klinostat's 

 action depends on the symmetrical distribution of stimuli, not on 

 their removal, we shall be compelled to take a different view of rec- 

 tipetality. To test this question a new form of horizontal klinostat 

 was devised. The axis of this instrument is not kept in constant 

 rotation, but at intervals of half-an hour it executes a half revo- 

 lution. A shoot or stem geotropically curved is fixed in the 

 klinostat so that the plane of curvature is horizontal. The suc- 

 cession of half turns prevents any geotropic distortion in the plane 

 at right angles to the original plane of curvature, while in that 

 plane the plant is free to increase or diminish its curvature apart 

 from any fresh gravitation-stimulus. The experiments show that 

 under these circumstances the curvature diminishes, and this can 

 only be due to an inherent regulating power, the rectipetality of 

 Vochting. 



The modified klinostat, which will probably be of use for 

 other purposes, was designed and made by the Cambridge Scien- 

 tific Instrument Company. 



(2) On the Occurrence of Bipalium Kewense, Moseley, in a 

 neiu Locality; with a Note upon the Urticating Organs. By 

 Arthur E. Shipley, M.A., Christ's College. 



[Received February 9, 1891.] 



Bipalium Kewense was first described by Professor Moseley in 

 the year 1878, from specimens obtained in the hot-houses at 

 Kew. In 1883 Dr Giinther received some examples of this species 

 from Welbeck Abbey, and one specimen was described from Clap- 

 ham Park. Mr O. Salvin exhibited some of these animals before 

 the Zoological Society in 1886, collected from amongst pieces of 

 broken tiles at the bottom of some pots of Calceolarias which had 

 stood in a cold frame all the winter in his garden near Haslemere, 

 Surrey. Some specimens from the same locality formed the object 

 of some interesting observations by Professor Jeffrey Bell during 

 the same year 1 . Finally the specimens which I am able, owing to 

 the kindness of Professor Newton, to exhibit to the Society this 

 evening came from the neighbourhood of Bath. 



1 Since writing the above, Prof. Herdman has informed me that Bipalium 

 Kewense was found in an Orchid house at Aigburth, near Liverpool in 1888, 

 and Mr Beddard writes to me that specimens are from time to time brought to him 

 from the gardening department of the Zoological Gardens. 



