106 RAY AND SOME OF HIS FELLOW-WORKERS 



development, and mode of life of birds. Tlie anatomical 

 part is largely taken from Willis and Harvey. The 

 sclerotic ring in the eye is mentioned. We are told of 

 the curious rule of the regular increase in the number of 

 the phalanges from the first to the last digit of the foot, 

 a rule which " hath not as yet been taken notice of by 

 any naturalist, that I know" (p. 3). Mention is made 

 of the exception furnished by the swift, in which "the 

 least toe has one joint, and the other three two joints 

 each, contrary to the manner of all other birds that we 

 know beside it" (p. 214). The muscles of flight are 

 mentioned, and we are assured that if men ever fly, it 

 must be with their legs. The wonderful protractile 

 tongue and the prolonged hyoid of the woodpecker are 

 explained and figured. This structure was afterwards 

 redescribed by De la Hire and M^ry, and became a 

 favourite proof of the wisdom of Providence. The 

 double-shafted feather of the cassowary, which had been 

 described and figured by Clusius, appears here again. 

 Under the head of development we find mention of the 

 fact that a fowl's egg cannot be easily crushed by the 

 fingers, if the pressure is applied to the two ends. It is 

 boldly afl&rmed that all animals, even viviparous animals, 

 proceed from eggs ; there was as yet no suspicion that an 

 animal may be budded forth from its parent. Twenty- 

 four questions are printed, which Willughby had pro- 

 posed to himself concerning birds, e.g. whether they cast 

 their claws and bills ; whether the iris is always of the 

 same colour in the same species ; a few of the questions 

 have answers appended to them. There is a brief 

 account of remarkable breeding-places of British birds. 



Aristotle had said^ that while some birds migrated 

 according to the season of the year, swallows did not, 



^ Hist. Animalium, VIII, 15. 



