L06 SUMMAEY OF CURRENT RESEARCHES RELATING TO 



No first class text-book dealing with the subject is, in our opinion, 

 likely to be published during the next half-century which does not draw 

 up' hi these rich store-houses of illustrations. 



(6) Miscellaneous. 



Sensibility of the Eye to Variations of Wave-length in the 

 Yellow Region of the Spectrum.* — From observations on his own 

 vision, Rayleigh concludes that the distinction in colour of the two 

 D lines can be perceived if favourably presented to the eye. 



Quekett Microscopical Club. — The -470th Ordinary Meeting was 

 held on January 24, the President, Professor E. A. Minchin, M.A. F.Z.S., 

 in the Chair. From particulars supplied by Mr. F. J. Keeley, of 

 Philadelphia, "who possesses a mount labelled " Navicula amicii, Florence, 

 Italy — from Professor Amici to C. A. Spencer," Mr. Nelson considers 

 the much-disputed Amician test to be certainly identical w r ith what he 

 terms the "English rhomboides" | Mr. C. F. Rousselet, F.R.M.S., de- 

 scribed and exhibited three new species of Rotifer. These are Anurse- 

 opsis navicula sp.n., from central Ceylon, a very small species, lorica 92 /a ; 

 Brachionus satanicus sp. n., from Devil's Lake, North Dakota, U.S.A. ; 

 and B. havaniensis sp. n., from Illinois River, near Havana. Mr. R. T. 

 Lewis, F.R.M.S., read a note " On the Larva of Mantispa." The dif- 

 ferences between mature specimens of the Mantidse family and those of 

 sub-family Mantispides are not very obvious to the casual observer. 

 Perhaps the most noticeable difference is in the life-history of the larvae 

 of the two groups. In Mantis, on emerging the young insects closely 

 resemble the adult form, except as to size, colour, and absence of wings. 

 In Mantispa the emerging larva? bear not the slightest resemblance to the 

 perfect insect. They are only about 1 mm. in length ; have two simple 

 eyes ; are armed with apparent mandibles ; have 3-jointed antenna? and 

 7-jointed palpi ; the six legs are of equal size, and are terminated by a 

 hollow trumpet-shaped appendage instead of the usual claws. On leav- 

 ing the egg the larva bores its way into the ovisac of a spider and feeds 

 upon the eggs or young until the second ecdysis. In the subsequent 

 stage it becomes a helpless, fleshy grub, and spins a cocoon. Emerging 

 from this it begins to resemble the perfect insect, but has only rudi- 

 mentary wings, and not until two more moults does it become a mature 

 Neuropterous Mantispa. Mr. H. Gunnery, of Acomb, York, exhibited 

 a number of preparations for the Microscope, mostly botanical sections, 

 and a series of lantern slides, mostly photomicrographs of various stages 

 of nuclear division in Lilium. The Microscopes used were kindly lent 

 by Messrs. C. Baker. 



Abney, Sir W. df. W. — Colour-blindness and the Trichromatic Theory of Colour 

 Vision. Parts i. and ii. 



[Part i. treats of the relation of complete, and Part ii. of incomplete, colour- 

 blindness to the trichromatic theory of colour vision.] 



Proc. Roy. Soc, Series A, lxxxiii.-lxxxiv. (1910) pp. 462-74 and 449-64. 



Blake sley, T. H. — A Means of Measuring the Apparent Diameter of the Pupil 

 of the Eye in very feeble Light. Phil. Mag., Dec. 1910. 



* Proc. Roy. Soc, Series A (1910) pp. 464-8. 



t See Journ. Quekett Micr. Club, ser. 2, xi. (1910) p. 95. 



