352 Dr. Paris on the Phi/siologi/ofthe Egg, [May^ 



contemplating life at a period when the number and complica- 

 tion of its functions are the least, becomes an irresistible induce- 

 ment to the physiologist to pursue the investigation : hence we 

 find that the philosophers of every age and nation have devoted 

 much time and labour to this inquiry. Unfortunately, however, 

 for science, the influence of chemical powers in the scheme of 

 animal life has only of late been investigated in reference to the 

 -problem ; but many beneficial results have already attended this 

 ^fiew train of research, and the most exhausted topics of natural 

 history have assumed novel and very unexpected aspects. The 

 author, therefore, of the present memoir may reasonably hope to 

 escape the censure which must otherwise have awaited the 

 adventurer who could presume to beat the field that has before 

 been so ably and diligently explored by the united labours of 

 Fabricius ab Aqua pendente, Harvey, Malpighi, Spallanzani, 

 Hunter, and other physiologists. A powerful phalanx of philoso- 

 phers maintain, with much plausibility, that the egg^' is the 

 ^universal womb of nature, and that oviparous differ only from 

 viviparous animals by the latter breaking their ovular bondage ^j* 

 before they escape from the parent. Concerning the truth of 

 this opinion, which is comprehended in the popular aphorism, 

 *' Omnia ex Ovo/' or with regard to the success with which the 

 eloquent Count de Buffon has levelled his shafts against the 

 partisans of this theory, I shall leave abler disputants to decide. 

 The observations which I am prepared to submit to your notice 

 do not involve the truth of either theory, but are connected only 

 with those animals that are oviparous, in the common accepta- 

 tion of the term ; that is, ivho deposit a germ to be developed by 

 causes totally independent of parental influence. 



Among the countless multitudes and varieties of animals, a 

 very small proportion only are viviparous, or produce living off- 

 spring : thus the immense tribes of birds, fishes, amphibious 

 animals, and insects, with comparatively few exceptions, J pro- 



♦ Egg. — The word Ovum seems to be derived from the Greek word O/ov, solita- 

 riuniy because it produces only one offspring; thus Fabricius " quia *i«^«/«/iflpariat, 

 non enim veluti caeteri uteri intra se plures gignunt foetus." That each egg should 

 include but one cmbryon seems to be a general law of nature, but not without its excep- 

 tions ; a singular species of egg was found by Mr. Folks, President of the Royal 

 Society, in the mud of a rivulet, which equalled in size a pin's head. By breaking the 

 shell he dislodged nine worms, all of which were contained within one involucrum. 



■f The system of the ovarists has been adopted by Harvey, Steno, Malpighi, Valis- 

 nieri, Duhamel, Nuck, Littre, Swammerdam, Haller, Spallanzani, Bonnet, &c. It 

 must not be forgotten that there are some animals that cannot be called oviparous in 

 whatever signification the term may be received ; the hydra^ for instance, multiplies its 

 species by sending off shoots from its own body, and may, therefore, be said to be gem,', 

 mtparous. 



J Some fish are viviparous, e.-g. Murcena AtiiruUla., or eel, Blcnnhis Viviparus^ &c. 

 Among the amphibia we may notice the viper, which brings forth its young alive, and 

 hence probably derives its name, quod vivum pnr'iat. Sj^allanzani considers also the 

 production of frogs as being rather of a viviparous than oviparous nature ; this rudi- 

 ment,- however, of the future animal certainly partakes as much of the nature of an egg 

 as of a foetus, and may probably be considered as a connecting link between the two 

 great classes. Insects likewise present us with exceptions, and several whiiaisical varie- 



