. Evolution and disease . ances which, in the absenceof more accurate information, have been interpreted asdue to inheritance of acquired conditions. The first instance concerns the tail feathers ofMomotiis; this bird has the singular habit of pickingaway the web of the central feathers of its tail untilthey assume a spatulatc condition. In consequence ofthe constant stripping of the web the feathers, whenthey first appear, are naturally narrower in the placeswhere they are habitually denuded. The habit ispractised by both sexes alike. The matter has beencarefully investigated by Mr. Salvin, w
. Evolution and disease . ances which, in the absenceof more accurate information, have been interpreted asdue to inheritance of acquired conditions. The first instance concerns the tail feathers ofMomotiis; this bird has the singular habit of pickingaway the web of the central feathers of its tail untilthey assume a spatulatc condition. In consequence ofthe constant stripping of the web the feathers, whenthey first appear, are naturally narrower in the placeswhere they are habitually denuded. The habit ispractised by both sexes alike. The matter has beencarefully investigated by Mr. Salvin, who is satisfiedthat this plucking process is practised by the motmots. These observations are interesting, for it is thoughtprobable that the spatulate or racket-shaped tails insome other birds may have been brought about in somesuch way, so as to become a permanent condition. All 186 EVOLUTION AND DISEASE. degrees may be met with, from a broad web to others inwhich the rachis of the tail feathers is clean from the Fig. 98.—The tail of the so-called Tailless Trout of Islay.
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectabnormalitieshuman
