DEFINITION AND CLASSIFICATION OF FRUITS. 47 



the unfertilized ooplasm dies without developing further, whereas the fertilized 

 ooplasm, after a longer or shorter period of rest, exhibits a characteristic growth 

 and becomes the point of origin of a young organism, the new generation. The 

 ooplasm rendered capable, by fertilization, of this particular kind of growth is 

 to be considered as an embryo, even in cases where no outwardly-visible change 

 in form, size, or colour has taken place. 



Both ooplasm and spermatoplasm are formed in special cells at definite spots 

 on a plant which is preparing to reproduce itself by means of fertilization. The 

 cell-chamber wherein the ooplasm is developed, and which is itself adapted to 

 the reception of foreign matter, and constitutes the point of origin of the embryo, 

 will in future be called an oogonium {i^ov = Qgg\ 761^05 = parentage); the cell wherein 

 the spermatoplasm is brought to the proper form and composition for the purpose 

 of fertilization is called an mitheridium in the case of a Cryptogam, and a pollen- 

 grain in the case of a Phanerogam. In a few instances the ooplasm is set free 

 from the oogonium and fertilized outside it; the oogonium has then, of course, 

 nothing more to do with the subsequent processes of development. In other cases 

 fertilization takes place within the oogonium; the oogonium persists in a more 

 or less altered form as the immediate envelope of the embryo, and is then 

 designated by the name of "carpium" (/capTrös = fruit), or briefly "carp". In yet 

 other instances it is possible, at the very earliest stages of development, to 

 distinguish a special multicellular envelope surrounding the oogonium. To this 

 envelope we may apply the term " amphigonium " in order to simplify the 

 terminology. If the amphigonium is later on converted into the coat of the 

 carpium, it may be called an "amphicarpium". In many plants this envelope 

 to the oogonium is succeeded externally by a second called a "pericarpium", which 

 will be the subject of more detailed study later on. 



Now what ought we to take to be the fruit? To try to conform to ordinary 

 usage, or to adopt the terms employed in other sciences, would cause fatal confusion. 

 The most expedient course, therefore, seems to be to put aside the names and 

 definitions adopted in other departments and to lay down an independent and 

 unambiguous definition of the plant-fruit, and apply it to all plants. Thus, from 

 the botanical point of view, we consider every structure to be a fruit which is the 

 product of fertilization, and at the same time constitutes the first step towards the 

 renewal of the fertilized plant. This definition includes the ooplasm, which is 

 fertilized outside the oogonial envelope, and forms the starting-point of a new 

 individual; there may, therefore, be fruits each consisting of nothing more than 

 an embryo. But usually the ooplasm is enveloped by a coat, which may be single 

 or double, or even threefold. Fertilization then takes place within these coverings, 

 and the influence of the spermatoplasm extends more or less beyond the ooplasm 

 to its investments. In such cases the coats also are involved in the process of 

 fruit-formation. They are stimulated to grow in a particular manner and take 

 the form of a mantle clothing the embryo, of a protective cover, or of some 

 contrivance which promotes the further development of the embryo and its full 



