1892.] MICKOSCOPICAL JOURNAL. 17 



neal and mounted in benzol-balsam. They are depigmented by an 

 aqueous solution of potassic hydrate (j%). — Bull. Mus. Comp. Zool. 



Dried Algae may be restored to fresh condition, even if quite black, 

 by the use of eau de javelle for maceration. — ^er. Deutsch. Bot. 

 Gesell. 



Resolution of Amphipleura Pellucida. — Mr. J. W. Gifford, F. 

 R. M. S., has examined a frustule with sodium light illumination un- 

 der which dots were unmistakably shown, and they became more 

 marked when the frustule was moved to the side of the field. He at- 

 tempted pliotographing them, using plates treated with an erythrosine 

 bath, but these plates were sensitive only so far down as the yellow part 

 of the spectrimi. Then a solution of iron perchloride was used as a 

 screen to cut off all the blue end of the spectrum. In this manner the 

 part used for photographing was reduced to a narrow band about mid- 

 way between the 1) and E lines of the solar spectrum. The markings 

 seemed to equal those claimed for S2iri7-cUa ocmma. He expressed 

 the opinion that in both cases they are simply multiplied rings of the 

 mid-rib and sides produced by the higher order of diffraction spectra ac- 

 cording to the Abbe theory. The mounts were of a sulphide of arsenic 

 derived from mixing sulphur and realgar, and difficult to make. 



With sodium light and a color-correct plate, achromatic object- 

 glasses work almost as well as apochromatic. The beads were not seen 

 with any glass of less than 1.4 aperture and the best results came with 

 Powell and Lealand's apochromatic i-io of 1.5 and achromatic i-20of 

 1.5 and 1-12 of 1.43. 



Zeiss' projection ocular was used. 



BIOLOGICAL NOTES. 



Sex Determined by Temperature. — Maupas finds that at the 

 commencement of oogenesis the g:^^ of a certain rotifer is neutral. If 

 temperature is lowered, females result; if increased, males result. — 

 CojHptes Rendus. 



Life After Desiccation. — Cobelli has dried some rotifers for over 

 five years, but after soaking a few days (3 to 7) the bodies distended 

 and under the microscope the internal organs are found to be in a good 

 state of preservation. — K. K. Zool. Bot. Gesell.., pp. ^85-6. 



Malaria parasites have been found in bii'ds. There are two kinds, 

 both possessed of a nucleus, which prevents calling them degenerations 

 of red corpuscles. — Centralbl. f. Bak. u. Par. ^ pp. 403^ 404. 



The Radish, which normally contains but little starch, may be in- 

 duced to secrete a large quantity if the seedlings are watered with salt 

 water. Lesage uses 4 gr. of sodium chloride to 1,000 gr. water. 



Hepatica triloba, which ordinarily has a 3-lobed leaf, has been ob- 

 served by Hildebrand to put up in two successive years 2-lobed leaves. 

 Other sudden changes of form are noted by him in Ber. Deutsch. Bot. 

 Gesell.., pp. 214-8. 



Jumping Seeds. — ■ Wistaria sinensis has been observed by Huth 

 to expel its seeds a distance of 10 meters (by night). He notes 48 gen- 

 era in which the fruit is violently expelled. These are of three classes : 



I. (i) Dry fruits in which the carpels roll up when ripe so as to ex- 

 pel the seeds. (Many leguminosai, etc.) (3) Climbing plants beai"- 



