Botany. 335 



nection with his histological studies has made a thorough exami- 

 nation of the morphological features as well, and has noted the 

 fact, previously overlooked, that the ovary in the two genera just 

 named is not strictly superior, as in the Loganiacew^ but half 

 inferior ; a trait of much interest considering their supposed rela- 

 tionship to the Rubiacece, which have inferior ovaries, b. l. e. 



4. tleber die Verbreitung der karpotropischen Nutations- 

 Jcriimmicngen der Nelch-, Hull-, und ahnlicher Blatter und der 

 BlUthenstiele ; by Anton Hansgirg. (Berichte der deutsch. bot. 

 Gesellsch., viii, pp. 345-355.) — By the term carpotropic the author 

 of this paper designates all movements of nutation which, occur- 

 ring after fertilization in the flower, assist either in the protection 

 of the young fruit or in the dissemination of the seed. These 

 movements resemble to a certain extent other kinds of nutation, 

 such as the nyctitropic movements, which tend to prevent too 

 great loss of warmth by radiation, or the so-called gamotropic 

 nutations, which directly or indirectly further fertilization ; but 

 the distinctness of their biological significance, which is at once 

 apparent, justifies their treatment as a separate class of phe- 

 nomena. The author first considers the cases of carpotropic 

 nutations of the calyx and floral bracts. Such movements are of 

 course confined to those plants in which these organs persist 

 during the development of the fruit. It is by no means the case, 

 however, that all plants with persistent calyx or bracts exhibit 

 phenomena of the kind. As in the occurrence of other varieties 

 of nutation, the carpotropic movements are more or less char- 

 acteristic of certain groups ; but they not infrequently occur, or 

 fail to appear, quite independently of the systematic affinities 

 of the plants. Thus although many species of Potentilla and 

 Fragaria exhibit such movements in a pronounced form, they 

 appear to be altogether absent in Waldsteinia. The first and 

 most readity observed form of carpotropic nutation in calyx and 

 bracts consists in their closing more or less firmly about the 

 young fruit, undoubtedly as protective envelopes. This phe- 

 nomenon Hansgirg has observed in over 150 genera of the 

 dicotyledons and about 40 of the monocotyledons. In plants 

 with inferior ovaries the surrounding bracts not infrequently 

 close about the fruit, just as the segments of the calyx do in 

 flowers with superior ovaries. Individuals of the same species 

 have sometimes been found to vary in the extent of their carpo- 

 tropic nutations. In regard to the mechanism by which these 

 movements are brought about, the treatment is brief and pro- 

 visional. The closing movements of the calyx and bracts which 

 are to be regarded as really carpotropic are, it is stated, the 

 result of hyponastic growth. From these, the author distinguishes 

 the purely passive movements by which a calyx, which has been 

 dilated by the expanding corolla, closes again upon the withering 

 of the petals. The subsequent opening of the calyx and bracts 

 (epinastic movement) for the escape of the mature seeds has also 

 been observed in a considerable number of cases, but is not 

 nearly so frequent as the movement of closing. 



