PReESH FACTS. 
A Srrance Dish. K. Kisuinovye. ‘Edible Medusae,” Zool. Jahrb. xii. 
1899, pp. 205-210, 1 pl. 1 fig. Mr. Kishinouye of the Imperial Fisheries 
Bureau, Tokyo, has described two rhizostomatous medusae (Rhopilema esculenta 
and Rh. verrucosa) which are used for food in Japan. The animal is preserved 
with a mixture of alum and salt or between steamed leaves of Kashiwa, a kind 
of oak, with the application of slight pressure. To prepare the preserved 
medusa for the table, it is soaked in water about half an hour, then taken out 
and well washed, cut into small pieces and flavoured. It is easily masticable 
and furnishes an agreeable food. It is also used as a bait for the capture of 
file-fish (JZonacanthus) and sea-breams (Pagrus). The latter are said to accom- 
pany shoals of the medusae. 
Aw Earty Cry. K. Fiscuer Sicwart. “ Biologische Beobachtungen an 
unsern Amphibien. ii. Der Laubfrosch, Hyla arborea, L.” Vierteljahrsschrift 
Nat. Ges. Ziirich. xliii. 1899, pp. 279-316, 1 pl. From this entertaining 
account of observations on the “ tree-frog” we select one note which is probably 
fresh. The observer has detected, quite apart from the breeding calls and the 
ordinary summer voice, a special strong cry of distress (‘‘ Angstschrei”) uttered 
on an occasion of peculiar anxiety. As amphibians were probably the first 
vertebrate animals to find a voice, this observation of a cry of distress or alarm 
has peculiar interest. 
WHAT IS THE DIFFERENCE BETWEEN A LAKE AND A Pond? Orto ZACHARIAS, 
“Ueber einige biologische Unterschiede zwischen Teichen und Seen,” iol. 
Centralbl. xix. 1899, pp. 313-318. The difference has hitherto been defined 
physically in terms of depth, etc. Thus R. Chodat, in his “ Ktudes de biologie 
lacustre,” says that the minimum average depth for a true lake is 20-30 metres. 
But Zacharias shows that there are also distinct bionomical differences in the 
plankton, various algae, rotifers, etc., being dominant in ponds and sparse in 
lakes, and vice versa ; and he substantiates this in some detail. 
ARTIFICIAL PRoDUCTION OF ALPINE CHARACTERS IN PLANTS. GASTON 
Bonnier. ‘‘Caracterés anatomiques et physiologiques des plantes rendues 
artificiellement alpines par l’alternances des températures extrémes,” Comptes 
Rendus Ac. Sci. Paris, exxviil. 1899, pp. 1143-1146. Continuing his experi- 
ments on this interesting subject, Bonnier finds that plants subjected to a daily 
alternation of extremes of temperature, tend to have more marked development 
of protective tissues, smaller and thicker leaves with a greater development of 
palisade tissue, frequent redness due to anthocyan, more assimilation per unit 
of surface, and relatively large flowers slightly less coloured than the normal. 
ANAL GLANDS oF Dytiscipar. Fr. Drerckz. “Sur la structure des 
Dytiscides et le prétendu rédle défensif de ces glandes,” Comptes Rendus Ac. 
Sci. Paris, exxviil. 1899, pp. 1126-1127. According to this investigator the 
anal gland of Dytiscus is a unicellular gland facilitating the respiratory function 
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