FRESH FACTS. 
INFLUENCE OF CoLD ON DEVELOPMENT. OSKAR SCHULTZE. ‘Ueber die 
Einwirkung niederer Temperatur auf die Entwickelung des Frosches,” Zweite 
Mitteilung, Anat. Anzeig. xvi. 1899, pp. 144-152. Prof. Schultze published a 
communication on this subject in 1895, in which he stated that subjection to 
zero temperature brought the development of the eggs of Rana fusca toa 
standstill. Further experiments have, however, convinced him that this is not 
the case. Even at zero the cell-divisions continue, though more slowly. He 
has not been able to bring about a complete non-fatal standstill in the frog’s 
development ; if it is producible, it must be by temperature below zero. 
A Snow-Worm. J. Percy Moorr. “A snow- inhabiting Enchytraeid 
(Mesenchytraeus solifugus Emery) collected by Mr. Henry G. Bryant on the 
Malaspina Glacier, Alaska,” Proc. Acad. Nat. Scr. Philadelphia, 1899, pp. 
125-144, 1 pl. A somewhat detailed account is given of the structure and 
habits of this worm, which has so remarkable a home. A very striking 
peculiarity is the yellow-brown, deep chocolate-brown, or almost black colour, 
and its opacity. Associated with it was a small Podurid, Achorutes nivicola, 
also black, and there are other instances. ‘It seems probable that some factor 
in a snowy environment lays the brand of melanism upon all the constituents 
of its invertebrate fauna.” But “zoological literature fairly bristles with 
attempted explanations of melanism.” The author discusses the physiological 
interest of an animal which lives and grows while maintaining a body temperature 
seldom varying much from the freezing-point of water. 
Facts or INHERITANCE. ERNEST WARREN. “An observation on inherit- 
ance in parthenogenesis,” Proc. Roy. Soc. Ixv. 1899, pp. 154-158, 1 fig. 
Dr. Warren has made measurements of successive generations of Daphnia 
magna, which, though insufficient in number, “appear to favour the view that 
inheritance in parthenogenetic generations resembles that from mid-grand- 
parent to grandchildren.” ‘If this kind of inheritance be found to hold at all 
generally in parthenogenesis, it would be a fact of very considerable significance, 
and might conceivably give some insight into the physiological causes of 
heredity and variation.” 
Has tHe Hac a Parieran Eve?. F. K. Stupnitxa. “Zur Kritik 
einiger Angaben iiber die Existenz eines Parietalauges bei Myxine glutinosa,” 
SB. béhmisch. Ges. Wiss. 1898 (published 1899), 4 pp. In one specimen of 
Myzxine, Dr. Beard observed in 1889 a distinct parietal eye, but Retzius, Saunders, 
and Leydig sought for it in vain. More recently, Studnitka has joined in the 
search, and is emphatic in declaring that there is no trace of the organ to be 
found. 
THYROID AND THyMuUs or AmpuHiBiaANS. HERMANN Bonav. ‘“Glandula 
thyreoidea und Glandula thymus der Amphibien,” Zool. Jahrb. xii. 1899, pp. 
657-710, 11 figs. Two kinds of thyroid occur, one with colloid vesicles, the 
other with a connective tissue meshwork including leucocytes and blood-vessels. 
The number on each side differs in nearly related forms, but there is never 
more than one colloid gland on each side. In Ecaudata the gland is always 
colloid except in Molge rusconii. The thymus is single on each side in 
Ecaudata and Caudata, except in the larval form of Amblystoma tigrinum, 
which has a variable number. In Siphonops, as Leydig has shown, there are 
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