Variation in animals and plants . 24°23°2r2r20019018017°16015°H013012°iri<r9° s° 7° g° 5 . 22. — Effect of temperature on growth of tadpole. highest temperatures employed the rate of develop-ment was respectively and times more rapidthan at the lowest. In the accompanying figure are reproduced the re- AND OF LIGHT. 227 suits obtained by O. Ilertwig * upon the ova of Ranafusca. The curves represent the number of days re-quired by the ova, kept at different temperatures, toreach certain definite stages. The ordinates indicatethe time in days after fertilisation, and the abscissae the
Variation in animals and plants . 24°23°2r2r20019018017°16015°H013012°iri<r9° s° 7° g° 5 . 22. — Effect of temperature on growth of tadpole. highest temperatures employed the rate of develop-ment was respectively and times more rapidthan at the lowest. In the accompanying figure are reproduced the re- AND OF LIGHT. 227 suits obtained by O. Ilertwig * upon the ova of Ranafusca. The curves represent the number of days re-quired by the ova, kept at different temperatures, toreach certain definite stages. The ordinates indicatethe time in days after fertilisation, and the abscissae thetemperature. For the lowest curve the stage to bereached was that of a gastrula with the blastopore clos-ing in, and we gather from this curve that the time re-quired at a temperature of 1° C. was 23 days; at a tem-perature of 6,° days, and at a temperature of 24°,only a single day. Stage II was that of an embryohaving a rudimentary medullary plate, with its edgesrising and separated by a broad cleft; Stage III
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Keywords: ., bookcentury1900, bookdecade1900, bookpublishernewyo, bookyear1902
