. The study of animal life. Zoology. Fig. 67.—Seasonal dimorphism of Papilio ajax; to tlie left the winter form (variety TeiaTnonides), to the right the summer form (variety Marcellus). (From Chambers's Encyclop.; after Weismann.) of which the winter forms are so different from those born in summer that they have often been described as different species. It is possible that this is a reminiscence of past climatic changes, such as those of the Ice Ages, as the. Fig. 68.—Seasonal changes of the bill in the puffin {Fratercula tirciicd); to the left the spring form, to the right the winter form,
. The study of animal life. Zoology. Fig. 67.—Seasonal dimorphism of Papilio ajax; to tlie left the winter form (variety TeiaTnonides), to the right the summer form (variety Marcellus). (From Chambers's Encyclop.; after Weismann.) of which the winter forms are so different from those born in summer that they have often been described as different species. It is possible that this is a reminiscence of past climatic changes, such as those of the Ice Ages, as the. Fig. 68.—Seasonal changes of the bill in the puffin {Fratercula tirciicd); to the left the spring form, to the right the winter form, both adult males. (After Bureau.) result of which a species became split up into two varieties. Thus Araschnia levana and Araschnia ^rorsa are respect- ively the winter and summer forms of one species. In the. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Thomson, J. Arthur (John Arthur), 1861-1933. New York, C. Scribner's sons [printed at the Edinburgh press]
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1892
