176 EMBRYOLOGY IN THE SEVENTEENTH [pt. 11 



ozs. dr. scr. grns. 



Another raw egg of the same sort ... 2 i 2 13 



Another 



The former egg boiled 



Lost in boiling 



The skin 



The shell 



The yolk 



The white 



2 I I 19 



.2 I I 18 



• - - - 15 



13 



- I 2 19 



- 5 - 7 

 I 2 - 13 



Loss in weighing 5 



Another early quantitative observation was that of Claude Perrault 

 who found about 1680 that developing ostrich eggs lost one-ninth 

 of their weight in five weeks. The Oxford Philosophical Society, 

 however, preferred as a rule to consider more unusual things, such 

 as "the egges of a parrot hatched in a woeman's bosome, a hen egg 

 figur'd like a bottle, a hen egg that at the big ende had a fleshie 

 excrescence, another hen-eg, monstrous, a suppos'd cocks egg, and 

 the eggs of a puffin, an elligug, and a razor-bill". Mention of these 

 different kinds of eggs reminds us that the systematic collection and 

 classification of eggs had been begun some years before by Sir Thomas 

 Browne (as may be seen in John Evelyn) and by John Tradescant. 

 About this time R. Waller made some noteworthy observations on 

 the "spawn of frogs and the production of Todpoles therefrom", 

 extending the work begun by Swammerdam not long before. 

 Mauriceau now gave a description of the phenomenon of sterile 

 foetal atrophy. The century fittingly closes with Michael Ettmiiller's 

 ponderous treatise, in which all the embryological work of the 

 seventeenth century is summarised with considerable accuracy. He 

 supported the moribund menstruation theory of embryogeny with 

 the argument that animals do not menstruate because they are more 

 prolific than men, and therefore all their blood is required for genera- 

 tion. Garmann's Oologia curiosa, which appeared in 1691, is worth 

 mention also, as a review of the knowledge of the time. But that his 

 work was what the booksellers' catalogues describe as "curious" is 

 shown by the following chapter-headings: De ovo mystico, rnpthico, 

 magico, mechanico, medico, spagyrico, magyrico, pharmaceutico. 



3-9. The Theories of Foetal Nutrition 



During the course of the seventeenth, and the first quarter of the 

 eighteenth, century, many theories were propounded concerning 

 foetal nutrition. It is convenient to classify them. 



