IN THE BODIES OF ANIMALS. 401 



naked eye, and the orifices of the tumid extremities of the 

 villi of the intestines, called by Lieberkuhn ampullce, are more 

 imaginary than real ; but, independently of this, the villi of the 

 intestines are wanting in by far the majority of animals, so 

 that in these absorption is carried on through excessively fine 

 pores, in a natural state quite incapable of transmitting the 

 eggs of worms. For a similar reason, the nutrient and se- 

 creting vessels distributed to the uterus, &c. are incapable of 

 depositing eggs by their minute radieles. The same objection 

 is afforded by an examination of the ultimate branches of the 

 pulmonary vessels, which form a net-work in the cells of the 

 bronchi. It is true that they carry red blood ; but would their 

 calibre admit the eggs of the larger worms — those of the 

 Lumbric worm for instance ? I have no hesitation in saying, 

 that one ovule of the Ascaris lumbricoides would conceal 

 many of the minute pulmonary vessels. A considerable time 

 ago, Werner made an arithmetical calculation, in which he 

 estimated the ovules of worms to be so diminutive as to allow of 

 their passing readily from one body to another with the san- 

 guineous globules ; in fact, that it was possible for them to be 

 transported from the uterus to the most remote parts of the 

 fcetal body. If, instead of an arithmetical computation, this 

 great naturalist had instituted a comparison of the relative 

 dimensions of these ovules and globules as seen under the 

 microscope, he would have arrived at a very different con- 

 clusion. Rudolphi has compared the ovules of Ascaris labiata 

 and Distoma polymorphum of the eel with globules of blood 

 procured from a small wound made in his own finger, both 

 being placed under the microscope. Globules of blood appeared 

 exceedingly minute when placed by the side of these ovules, 

 although the worms are not large. An ovule of the Ascaris, 

 indeed, exceeded a globule in diameter by ten or twenty times. 

 Let us, then, be careful how we admit an hypothesis which, 

 like this, is so encumbered with inconsistencies. It is impos- 

 sible that such ova can traverse those vessels which are sub- 

 servient to nutrition, and it is certain that the red globules do 

 not. I think that enough has been said to prove the falsity of 

 this theory ; but if another argument is wanting, we possess it 

 in the fact, that if the ovules are carried to the uterus and 

 ovaries through the medium of the absorbent and sanguiferous 

 systems, we must assume that every part of the body abounds 



NO. IV. VOL. III. 3 F 



