THE FEMALE GAMETOPHYTE 97 



and inactive, or relatively persistent and active, for the grada- 

 tions between these two extreme conditions are complete. It 

 is noticeable, however, that the two conditions are apt to be 

 characteristic of families, and that the most extensive develop- 

 ment of the antipodal cells is found in comparatively few 

 families. 



It is needless to attempt to give a complete list of those 

 families in which the antipodal cells are ephemeral, disorgan- 

 izing with more or less rapidity, and apparently taking no part 

 in the activities of the embryo-sac. The following data will 

 serve to illustrate that this condition is found in groups of 

 every rank. Among Monocotyledons, ephemeral antipodal? 

 are found in Typhaceae, Xaiadaceae (Potamogeton), Alisma- 

 ceae, Pontederiaceae, Liliaeeae (except Omithogalum), Sci- 

 tamineae, and Orchidaceae; among Archichlamydeae, in Sau- 

 ruraceae, Salicaceae, probably Casuarinaceae, Cupuliferae, 

 Loranthaceae (Loranthus), Caryophyllaceae, Cruciferae, Saxi- 

 fragaceae, Leguminosae. Euphorbiaceae, Aceraceae, Cactaceae, 

 Onagraceae, and Umbelliferae ; and among the Sympetalae, in 

 Oleaceae, Bignoniaceae, Pedaliaceae, Scrophulariaceae and 

 their allies, and certain Itubiaceae. A certain amount of varia- 

 tion in these families has been found, as will be noted later, 

 and doubtless much more will be found as other species are 

 investigated. It will also be noted that this condition is 

 probably not so prevalent in the Sympetalae as in the other 

 groups. 



In those antipodal cells that function more or less there is 

 every degree of prominence. It should also be noted that antip- 

 odal s of the same sac often differ very much in prominence. For 

 example, in Lilium the innermost antipodal is often the most 

 prominent, in Nicotiana (Guignard 107 ) they are often unequal 

 in size, among the Galieae (Lloyd 105 ) one of the three is much 

 elongated, and among the Compositae the one nearest the cha- 

 laza is often very much enlarged (Fig. 47). The simplest cases 

 are those in which the cells do not grow very large or divide, 

 but by their prominence and persistence indicate that they are 

 taking some part in the activities of the embryo-sac, as in 

 Viscum, Xyctaginaceae, Ruta, Polygala, F>ont</<>, Salvia, Xico- 

 ti'ina, and Sarcodes, as well as certain members of families 

 characterized by a striking development of the antipodal cells. 



