. The story of the birds; . fihula^ or the smaller of the leg bones,that they might run better. Likewise, later they lostsome muscles that were necessary in running, swim-ming, or moving the tail even ; and they had variousadhesions of the tendons in keeping with their wants. They took on certain oigans as they had need,and lost these new ones as readily when they became 193 PROFIT AND LOSS IN THE BIRDS. 193 useless by change of habit. But some of them per-sist yet as vestiges of past conditions. When birdstook to water they developed webs between the toes,and their toe tendons spHt up and spr
. The story of the birds; . fihula^ or the smaller of the leg bones,that they might run better. Likewise, later they lostsome muscles that were necessary in running, swim-ming, or moving the tail even ; and they had variousadhesions of the tendons in keeping with their wants. They took on certain oigans as they had need,and lost these new ones as readily when they became 193 PROFIT AND LOSS IN THE BIRDS. 193 useless by change of habit. But some of them per-sist yet as vestiges of past conditions. When birdstook to water they developed webs between the toes,and their toe tendons spHt up and spread out to eachdigit, in keeping with very comphcated needs. Yes-tiges of these persist (in tlie fowls, birds of prey,and others) with peculiar arrangements of tendons topull the outer toes in under the middle, as if to offerlittle resistance to the water on the forward swimmingstroke. Many of the lower birds that are not swim-mers retain a muscle whose sole use was to close thefront toes automatically when the leg is (S^
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectbirds, bookyear1897
