314 CONSIDERATIONS RESPECTING 



follow tlie same rule. Thus, the anomaly is an illustration and con- 

 firmation of a law, known by otlier means and of essential importance 

 for the right understanding of the plan of a flower. 



For affording striking proofs of the general laws of structure, for 

 overcoming peculiar difficulties attending the explanation of particular 

 cases, and, with the aid of the study of embryonic development, and 

 of the homologous parts of other, more especially of kindred, species, 

 for unfolding obscure, but most interesting theoretic principles, we 

 have no method so efficient as the study of anomalies ; and it is not 

 too much to say that much of the philosophic interest communicated 

 to botanical science of late years is derived from it. The variety of 

 anomalous forms is so great, that without a clear arrangement, we can- 

 not hope to take a comprehensive view of their nature, and the appli- 

 cations of which they are susceptible. In conformity with the views 

 I have given of the causes of anomalous developments, I think they 

 may all be reduced to three classes, the first consisting of cases in 

 which the development is diminished, the second of those in which it 

 is increased, and the third, of those in which its direction is altered ; 

 a fourth class would include those which depend on internal changes 

 in the contents of the cells, producing unusual modifications of colour, 

 but these I shall not further notice at present. The first class may be 

 subdivided into 1. Suppression of organs, 2. Degenerescent transforma- 

 tions, and 3. Separations of parts. In the second class we have, 1. 

 Reappearances of parts rudimentally existing, but which are normally 

 suppressed in the species ; 2. Comparative enlargement of particular 

 circles ; 3. Transformations due to increased development ; 4. Cohe- 

 rences and adherences ; 5. Multiplication of circles ; 6. Production 

 of extraneous appendages to particular organs. In the third class we 

 have : 1. Cases of irregularity where the usual structure is regular ; 

 2. Cases of return to regularity in 'species usually irregular. All 

 these secondary divisions may be further subdivided according to the 

 part affected, and we have thus a view of the whole subject, exhausting 

 the possible cases, and presenting them in an order of mutual relation 

 such that the mere reference of each case to its proper position im- 

 plies the attainment of much valuable knowledge. 



To give by description and figures examples of each class and 

 subdivision would occupy too great space, without the objects brought 

 forward being generally new. I rather select a few examples illus- 

 trative of the importance of anomalies in suggesting or confirming 

 theoretical truths, or explanations of structures otherwise unintel- 

 ligible. 



