[3] Wolff was the first to call attention to the great importance of the study of development. He was followed by Turpin, Mirbel, Schleiden, Payer, and others, and its value is now fully recognised by botanists. [4] Agardh, "Theoria Syst. Plant.," p. xxiii. [5] In the memoirs of Hopkirk, Kirschleger, Cramer, Hallier, and others, malformations are arranged primarily according to the organs affected, an arrangement which has only convenience to justify it. It is hoped that the index and the headings to the paragraphs in the present volume will suit the convenience of the reader as well as if the more artificial plan just alluded to had been adopted. [6] Cryptogamous plants are only incidentally alluded to in these pages, owing to their wide difference in structure from flowering plants. Attention may, also, here be called to a paper of M. de Seynes in a recent number of the Bulletin of the Botanical Society of France, vol. xiv, p. 290, tab. 5 et 6, in which numerous cases of malformation among agarics are recorded. See also same publication, vol. iv, p. 744; vol. v, p. 211; vol. vi, p. 496. [7] On this subject see a paper of M. Naudin in the 'Comptes Rendus,' 1867, t. 64, pp. 929-933. [8] It is probable that many terms and expressions calculated to mislead in the way above mentioned are made use of in the following pages. The inconsistency manifested by their use may be excused on the ground of ignorance of the true structure, and by the circumstance that in many cases facts alone are recorded without an explanation of them being offered. Moreover, it is desirable to act in conformity with the usual practice of botanical writers, and not to change established terminology, even if suspected to convey false ideas, until the true condition of affairs be thoroughly well ascertained by organogenetic research or other means. [9] A curious illustration of the latter class of alterations came under the writer's notice last summer (1868), and which he has reason to believe has not been previously recorded, viz. the persistence in an unwithered state of the petals at the base of the ripe fruit, in a strawberry. All the fruits on the particular plants alluded to were thus provided as it were with a white frill. Whether this be a constant occurrence in the particular variety is not known. VEGETABLE TERATOLOGY. BOOK I. DEVIATIONS FROM THE ORDINARY ARRANGEMENT OF ORGANS. As full details relating to the disposition or arrangement of the general organs of flowering plants are given in all the ordinary text-books, it is only necessary in this place to allude to the main facts at present known, and which serve as the standard of comparison with which all morphological changes are compared.