the Origin of Intestinal IVorms. 337 



subsequently however done by Dr Siebold (in Burdach Phys. 

 1. c). The analogy between an egg and a primitive cell can 

 rarely be more evident than in this instance. My attempts to 

 ascertain the number of ova in one female yielded the follow- 

 ing results : — The free end of the ovary is but l-25th of a line 

 in diameter. A transversal section of the ovary (fig. 1) shews 

 the number of ova around the rachis to be about 50, and 

 their diameter to be about l-500th part of a line. Hence, in 

 the space of one line there will be 500 wreaths or stars of 50 

 eggs each, so affording 25,000 ova. The length of each horn 

 of the female organ is about 16 feet or 2304 lines, which, for 

 the two horns, gives 4603 lines. If the ova, therefore, were 

 of the same diameter throughout, their number would amount 

 to 25,000 X 4608, but as they augment in size as they pro- 

 ceed from the ovary to the uterus, till at last they attain a dia- 

 meter of l-60th of a line, they will not form more than 60 

 wreaths or 3000 eggs in one line within the uterus. Thus, 

 supposing the diameter of the eggs to increase proportionally 

 throughout the length of the female organs, we may calculate 



^, , « .25.000 + 3000 1. ^^^ 

 the number of ova, on an average, at — ^ ^ , or 14,000 



in each line ; giving the total number of eggs at 14,000 x 

 4608, of course more than 64,000,000, a fertility equalled only 

 by that of some fishes. 



Sect. 3. Example from the Strong^lus inflexus. — In the 

 other Nematoidea the female organs are generally formed on 

 the same plan, and they are rarely less complicated. I shall 

 here adduce another example, viz. that of the Strongylus inflexus 

 (Rud.). This worm is extremely common in the bronchiae of the 

 Delphinus phccana^ and has been described by Rudolphi (Hist. 

 Yerm. vol. ii. p. 1 and 227) ; by Creplin (Nova? Observationes 

 de Entozois, Bed. 1829, p. 17-19), and by Dr Craigie of Edin- 

 burgh (Edin. Medical and Surg. Journal, vol. xxxviii. p. 301 

 and 354, Edinburgh, 1832). The last-mentioned author has 

 in many respects given the best description, but the advan- 

 tage which science might have derived from his labours was 

 in a great measure lost, because he at first mistook the poste- 

 rior extremity for the anterior, and thus regarded it as a new 

 species. In a supplementary paper in the same volume, he 

 corrected this blunder^ but unfortunately this second pftpcr 



