1873.] 183 [McCrady. 



My own incomplete observations upon Bucephalus cuculus left me 

 under some doubt whether in that case, as in the Hydroids, there 

 was not actually a frustration of the entire contents of the sporo- 

 cyst, in the production of the more advanced stage. The more defi- 

 nite observations of Lacaze-Duthiers seem, however, to settle the 

 question that the process is one of internal gemmation, and this coin- 

 cides with what is observed in other Cercarian forms. Nothing of 

 this kind has been observed among Hydroids, unless we admit the 

 case of supposed "Alloeogenesis," contended for by Haeckel; in which 

 he regards the young Cunina as budded out from the columella of 

 Geryonia, upon which they are found. Notwithstanding my recogni- 

 tion of Haeckel's great abilities, and his extremely valuable labors as 

 an original investigator, I cannot admit his interpretation of these 

 observations. It is impossible to imagine that a remarkable form like 

 Cunina should be developed by gemmation, both from a Turritopsis 

 and a Geryonia; and that notwithstanding there should be no more 

 than a specific difference between the Cunina from the one, and that 

 from the other; and nothing proves more forcibly the profoundly dis- 

 organizing tendency of the Darwinian view of an indefinite and 

 practically lawless tendency to variation and transmutation, than 

 that so able an observer should propound such a view of the 

 facts in this case. There is, in my opinion, no evidence from the 

 observations of Fritz Muller and Haeckel, that there is any gem- 

 mation at all. The fact observed by both appears to be that the 

 very youngest form of the larval Cunina is a very small planula, 

 which adheres so closely to the epithelium of the stomach of its 

 host, as to appear merely as a thickening of that membrane. When, 

 as a beginner in embryological research, I made the mistake of sup- 

 posing the parasitic Cunina larvae to be young of Turritopsis, I was 

 misled by the analogy of Tubularia nursing its own embryos, but cor- 

 rected my mistake in the later stages of my research. That Prof. 

 Haeckel can imagine my first interpretation more correct than my 

 second, I can only explain as one of the miracles wrought by the 

 hypothesis of transmutation. Not only is the budding of one sex- 

 ually mature form from another and a different sexually mature 

 form, a thing so contrary to what we know of development, and so 

 unparalleled by all our observations as to require incontrovertible 

 proof before it could be accepted, but the assumed fact depended 

 on for proof in this case, namely, the origination of an animal as a 

 bud from the mere thickening of a mere epithelium (an already quite 



