Vegetable Teratology | Page 6

the one from the other, we shall arrive at conclusions which will be more or less generally accurate or applicable, according to the ability of the student and the extent to which the comparative analysis is earned. It is thus that morphologists have been enabled to frame types or standards of reference, and systematists to collocate the organisms they deal with into groups. These standards and groups are more or less artificial (none can be entirely natural) in proportion to the amount of knowledge possessed by their framers, and the use they make of it.
From this point of view teratological metamorphosis of all three kinds demands as much attention as that which is called normal. We can have no thorough knowledge of an organ, of an individual which is an aggregate of organs, or of an aggregate of individuals of whatever degree, unless we know approximately, at least, what are the limits of each. It is not possible to trace these limits accurately in the case of natural science, but the larger our knowledge and the wider our generalisations, the closer will be our approach to the truth.
The most satisfactory classification of malformations would be one founded upon the nature of the causes inducing the several changes. Thus, in all organised beings, there is a process of growth, mere increase in bulk as it were, and a process of evolution or metamorphosis, in accordance with which certain parts assume a different form from the rest, in order the better to fit them for the performance of different offices. Should growth and development be uniform and regular, that is in accordance with what is habitual in any particular species, there is no monstrosity, but if either growth or development be in any way irregular, malformation results. Hence, theoretically, the best way of grouping cases of malformation would be according as they are the consequences of:--1st. Arrest of Growth; 2ndly. Excessive Growth; 3rdly. Arrest of Development; 4thly, of Excessive or Irregular Development.
In practice, however, there are so many objections to this plan that it has not been found practicable to carry it out. The inability arises to a great extent from our ignorance of what should be attributed to arrest of growth, what to excess of development, and so on. Moreover, a student with a malformed plant before him must necessarily ascertain in what way it is malformed before he can understand how it became so, and for this purpose any scheme that will enable him readily to detect the kind of monstrosity he is examining, even though it be confessedly artificial and imperfect will be better than a more philosophical arrangement which circumstances prevent him from employing.
The plan followed in this volume is a slight modification of that adopted by Moquin-Tandon, and with several additions. In it the aim is to place before the student certain salient and easily recognisable points by reference to which the desired information can readily be found. Under each subdivision will be found general explanatory remarks, illustrative details, and usually a summary of the more important facts and the inferences to be derived from them. Bibliographical references and lists of the plants most frequently affected with particular malformations are also given. In reference to both these points it must be remembered that absolute completeness is not aimed at; had such fullness of detail been possible of attainment it would have necessitated for its publication a much larger volume than the present.[5] It is hoped that both the lists of books and of plants are sufficiently full for all general purposes.[6]
In the enumeration of plants affected with various malformations the ! denotes that the writer has himself seen examples of the deviation in question in the particular plant named, while the prefix of the * indicates that the malformation occurs with special frequency in the particular plant to which the sign is attached.
Teratological alterations are rarely isolated phenomena, far more generally they are associated with other and often compensatory changes. Hence it is often necessary, in studying any given malformation, to refer to two or more subdivisions, and in this way a certain amount of repetition becomes unavoidable. The details of the several cases of malformation given in these pages are generally arranged according to their apparent degree of importance. Thus, in a case of prolification associated with multiplication of the petals, the former change is a greater deviation from the customary form than the latter, hence reference should be made, in the first instance, to the sections treating on prolification, and afterwards to those on multiplication. To facilitate such research, numerous cross references are supplied.
In the investigation of teratological phenomena constant reference must be made to the normal condition, and vice versa, else neither the one nor the other can be thoroughly understood. It cannot, however,