Taxonomic Ayiomalies 659 



with the theory of sudden mutation. Together 

 these two conceptions go to strengthen the prob- 

 ability of the sudden origin of all specific char- 

 acters. 



Experimental researches are limited in their 

 extent, and the number of cases of direct obser- 

 vation of the process of mutation will probably 

 never become large enough to cover the whole 

 field of the theory of descent. Therefore it will 

 always be necessary to show that the similarity 

 between observed and other cases is such as to 

 lift above all doubt the assertion of their result- 

 ing from the same causes. 



Besides the direct comparison of the muta- 

 tions described in our former lectures, with the 

 analogous cases of the horticultural and natural 

 production of species and varieties at large, an- 

 other way is open to obtain the required proof. 

 It is the study of the phenomena, designated by 

 Casimir de Candolle with the name of taxo- 

 nomic anomalies. It is the assertion that char- 

 acters, which are specific in one case, may be 

 observed to arise as anomalies or as varieties in 

 other instances. If they can be shown to be 

 identical or nearly so in both, it is obviously 

 allowable to assume the same origin for the 

 specific character and for the anomaly. In 

 other terms, the specific marks may be consid- 

 ered as having originated according to the laws 



