392 An Examination of the Opinions of Bremser and Others 



who, after having devoted much patient investigation to the sub- 

 jectj adhere to the opposite opinion of the spontaneous formation of 

 animal life.* As the arguments of Dr. Bremser are those gene- 

 rally adopted by the advocates of this latter opinion, we shall state 

 them briefly here. 



The certainty, says he, orspontaneous generation is estabKshed, 



\st, By the negative proof that the eggs of intestinal worms can- 

 not come from without. 



2d, From the analogy of the infusoria.- 



3rf, From induction drawn from the primitive formation of the 

 animal kingdom. 



Thus the first and principal proof of a spontaneous formation is 

 the assumption of the impossibility of the eggs of intestinal worms 

 being conveyed into the body from without, — Worms are found to 

 exist in the internal cavities of the body. Their eggs cannot be 

 distinctly traced entering these cavities ; therefore these worms 

 must have sprung, by a spontaneous creation, from the parts by 

 which they are surrounded. Now, there are many of the minute 

 operations of nature which we cannot distinctly trace, — many evi- 

 dent effects which must be the result of causes however obscure. 

 We cannot explain how the yelk of the hen, after it has burst its 

 calyx, is taken up by the fimbriated mouth of the infundibulum ; 

 yet we are certain, from daily results, that such a process takes 

 place. The oviducts of the common frog terminate in two open 

 mouths at the sides of the heart, — the ovaria of the same animal 

 lie under the liver. Now here is a difiiculty to understand how 

 they should communicate. We cannot even tell by what process 

 an ovum in the human species enters the Fallopian tube, to be 

 hence conveyed to the uterus, and yet that it does so, by some 

 means or other, there can be no doubt. And are not these cases 

 of as apparent difiiculty as the transmission of the minute egg of 

 the Distoma hepaticum to the liver, or that of the Hydatid to the 

 brain, and certainly much more so than the conveyance of the eggs 

 of the common worms of the intestines ? 



The blight in wheat, f says Sir E, Home, is produced by a worm 

 which is met with in all the stages of its growth. \V"hen full 

 grown this worm is scarcely visible to the naked eye, but in the 

 field of the microscope all its parts are readily distinguished : eggs 

 are also seen in the belly, and detected passing out. The worms, 

 when placed in a drop of water on the field of the microscope, are 

 seen to move briskly about ; but if the water is allowed to evapo- 

 rate, a stain is left on the glass scarcely perceptible, — when water 

 again is added, they revive and move. This experiment has been 

 made at intervals of months during a period of six years, and 



* Among Aese may be enumerated Blumenbach, Darwin, Cuvier, Bory de 

 St. Vincent, Rudolphi, and Bremser. 

 f Purples, ear-cockle, smut. 



