174 



NATURE 



[October 30, 1919 



the accelerating effect of light stimulation of sub- 

 minimal intensity, 



K^ect oj Strong 5ti)n«!ui-.— Experiment 2 : The 

 maximum energy radiated by my transmitter, as 

 stated before, was only moderate. In spite of this, 

 its effect on plants was exhibited in a very striking 

 manner. The balance was immediately upset, indi- 

 cating a retardation of the rate of growth. The 

 latent period, i.e. the interval between the incident 

 wave and the response, was only a few seconds 

 (Fig- 2, (b)). The record given in the figure was ob- 

 tained with the moderate magnification of 2000 times 

 only; but with my crescograph the magnification can 

 easily be raised ten million times, and the perception 

 of plant to the space-signalling can be exalted in the 

 same proportion- 

 Under an intensity of stimulus slightly above the 

 subminimal, the response exhibits retardation of 

 growth followed by quick recovery, as seen in the 

 series of records given in Fig. 2, (c). The perceptive 

 range of the plant is inconceivably greater than ours; 

 it not only perceives, but also responds to the different 

 rays of the vast ethereal spectrum. J. C. Bose. 

 Calcutta, August 16. 



A New British Enchytrxld Worm. 



In a collection of worms brought from Lapworth 

 by Mr. Hillman on August 11, I found one which is 

 new to this country, and of great interest on 

 account of its unusual character and relationships. 

 In 1877 Vejdovsky described his Pachydrilus sphagne- 

 torum. Eleven years later Michaelsen added to it a 

 variety named glandulosus. In course of time the 

 name Pachydrilus was changed to Marionina, and 

 the two worms above-named were placed as distinct 

 species under this genus, forming a section by them- 

 selves on account of their aberrance. They both had 

 the girdle thrown forward, the spermathecas were 

 free in the ccelom, the septal glands were more 

 numerous than in the type, and there were other 

 peculiarities. In Michaelsen 's " Oligochaeta," pub- 

 lished in 1900, they appear as Marionina sphagne. 

 torum, Vejd., and M. gLandulosa, Mich. 



In 1913 1 described a new British Enchvtrseid 

 (Chamaedrilus chlorophilus. Friend), which cou'ld not 

 be fitted into any then known genus. Its relation- 

 ships were discussed and its aflinities with the two 

 aberrant Marioninas pointed out. On finding 

 M. glandulosa, I was for a time in doubt about its 

 true name, as it so closely resembled Chamadrilus. 

 Careful study, however, shows that the three worms 

 are very nearly related, and must be referred to one 

 and the same genus. In Marionina the blood is 

 slightly coloured, in Chaniaedrilus it is quite colour- 

 less. In the jformer the spermathecae are free, 

 whereas in ChamEedrilus they are attached to the 

 intestine. In all other respects they agree. The for- 

 ward position of the girdle, the shape and number 

 of the setae, absence of salivary glands, form of 

 spermathecae, size of coelomic corpuscles and 

 chloragogen cells, enlarged number of septal glan*^, 

 incised brain, and other important characters, all 

 point to one genus. 



They are exceedingly slender worms, and Vejdovsky 

 has pointed out a peculiarity in M. sphagnetorum 

 which is of special interest. Like certain water- 

 worms, it can multiply by subdivision. We have 

 here, very clearly, a genus which links the Enchy- 

 trseids with some of the other families of worms. 

 Details cannot be discussed now, but it is evident 

 that we shall for the present have to regard the genus 

 Chamsedrilus as consisting in this country of three 

 species, viz. Chamaedrilus sphagnetorum, Vejd., 



NO. 2609, VOL. 104] 



C. glandulosus, Mich., and C. chlorophilus. Friend. 

 The generic characters are roughly as follows : — 



Cham^drilus. — Girdle advanced to segment 10, g, 

 or 8; nephridia begin in 8/9 or 9/10; spermathecae 

 with posterior outgrowth, either free or attached to 

 the intestine ; coelomic corpuscles' and chloragogen 

 cells large ; blood colourless or but slightly tinged 

 with yellow or red ; the dorsal vessel originating 

 behind the girdle and possessing no anterior com- 

 missures (apparently). Salivary gland absent, brain 

 deeply incised. Related to Stercutus and Bryodrilus. 



HiLDERic Friend. 



"Cathay," Solihull, September 24. 



A Photoelectric Theory of Colour Vision. 



In view of the recent letters from Prof. Joly and 

 Sir Oliver Lodge under the above heading, I may be 

 allowed to point out that such a theory of colour vision 

 was advanced by me in a lecture delivered before the 

 Rontgen Society on January 7 last, and published in 

 the Journal of the society for April. After referring 

 to Prof. Joly's views as to the nature of the change 

 taking place in the formation of the latent image and 

 in radio-therapy, I said : " In my opinion, it is un- 

 necessary to assume that a photochemical change is 

 the cause of the visual sensation. It appears to me 

 sufficient to suppose that photoelectric action takes 

 place in the rods or cones, so that we have a separa- 

 tion of electrons resulting in electrification of the 

 nerve-cells which set up the nervous impulse to the 

 sensorium." A number of familiar facts were adduced 

 in support of this view, and it was mentioned that 

 the peaked curve which shows the relation between 

 the sensitiveness of the eye for light of different wave- 

 lengths bears a verv close resemblance to the curve 

 which shows the variation of photoelectric activij 

 with wave-length. H. Stanley .Allen, 



Luminous Worms. 



Around Nottingham forty-five years ago it was 

 common practice among anglers to search the 

 meadows by aid of a lantern for "dew-worms and 

 cockspurs," as they were locally known. .After col- 

 lection they were placed in damp moss in a dark shed 

 for a few days until they were "scoured"; this 

 brought them into condition, and rendered them more 

 attractive as bait and fresher and redder in colour. 

 After this treatment worms were phosphorescent for 

 about one-fourth of the entire length of the body, 

 while the light was most noticeable in the ventral 

 region. H. E. .Aldridce. 



40 Great Queen Street, Dartford. 



RECONSTRUCTION. 



IT has been a reproach, not without foundation, 

 frequently cast at the British Empire that 

 there has been hitherto a lack of reasonable and 

 sufficient organisation. The circumstances arising 

 out of a state of war have led necessarily to the 

 institution of a number of new Departments which 

 have been called into existence hastily and without 

 adequate consideration. Some of these will, of 

 course, disappear, and others will remain to be 

 reconstituted. In view of these facts the Govern- 

 ment did wisely in July, 1917, in appointing a 

 Committee with the purpose of considering the 

 changes which would become necessary after 

 the war, and the report of one of its Sub-Com- 

 mittees, that on the Machinery of Government, 



