ZOOLOGY AND BOTANY, MICROSCOPY. ETC. 607 



p. Physiolog-y.* 

 (1) Reproduction and Germination. 



Diclinism and Hermaphroditism. t — Starting from an examinatif n 

 of the phenomena of reproduction in Limnohium stoloniferum (Hydro- 

 charidete), Heir U. Hammer conilufles that the original condition in 

 flowering plants is that of monac'sm, from which dioecism and herma- 

 phrodit'smhave been derived, and that the highest conceivalde condition 

 is where heterostjlcd dichogamous hermaphrodite are densely aggregated 

 along with diclinous flowers, such as we tind in the cap; tula of Com- 

 positae ; pollination being here secureil, but self-fertilization prevented. 

 This order he regards, therefore, as the highest existing form of 

 Dicotyledons, and the Orchidefe of Monocotyledons, while the Hydro- 

 charidese, in which hermajihroditism is very rare, represents one of the 

 oldest branches of the latter group. A detailed description follows of 

 the anatomy, morphology, and biology of the species named. 



Trimorphism of Oxalis.J— Mr. W. G. Eliot and Prof W. Trelease 

 give a series of measurements of the length of style and tilaments in the 

 three forms of the American trimor])hic species of Oxalis. They regard 

 trimorphism as a device f >r surer and more abundant cross-fertilization. 

 The relative number of long-styled, short-styled, and mid-styled forma 

 observed was about in the proportion of four, five, and eleven. 



Pollination by Lepidoptera.§ — Sig. G. E. Mattel describes the 

 adaptation of the proboscis of lepidoptera for obtaining the honey of 

 flowers ; and of the flowers themselves for receiving the visits of the 

 insects. He enumerates 132 si)hingophilous species, characterized by 

 blossoming in the evening or night ; by their strong odour, especially 

 at night; white or yellowish C(dour; long, slender, often curved tubular 

 corolla or spur, yielding abundance of honey ; viscid or united pollen- 

 gi ains ; and by their usually projecting stigma and stamens, often with 

 very motile filaments. 



Perforation of Flowers by Insects. |1 — Mr. L. H. Pammel, after 

 describing the mode of fertilization of Phlomis tuherosa, enumerates the 

 instances in which the corolla of flowers is known to be perforated by 

 insects or birds in order to obtain the nectar. The insects with which 

 this is habitual are mostly species of Bombus, the hive-bee most 

 commonly making use of perforations already made by otlier insects. 

 The tendency is to produce sterility by preventing pollination in the 

 ordinary way, though this is by no means always the case. The per- 

 foration of the corolla is usually attributable to the non-adaptability of 

 the insect to the flower, and the insect often uses considerable ingenuity 

 in perforating the flower, attacking it in close proximity to the nectary. 

 This is individual and not inherited experience on the part of the insects. 

 Phlomis tuherosa and Sijmjihytum officinale are exnmples of flowers which 

 are abundantly perforated, and are yet very productive. 



* This subdivision contains (1) Reproduction and Germination; (2) X'utriiion 

 and Growth (niclu.ing Moveiuents of Fluids); (3) Irritability; and (4) Chemical 

 Changes (including Keopiration and Fermentation). 



t 'Beitr. z. Kenut. d. veget. Organen v. Limnohium stoloniferum Griseb., nebst 

 einigen Betiachtuugen idx d. phylogcnetische Dignitat v. Diclinie u. Heruiaphro- 

 ditisQius,' 17 pp., Berlin, 1S88. See Bot. Centralbl., xxxviii. (1889) p. 743. 



X Trans. Acad. Sci. St. Louis, v. (1888) pp. 278-91 (S figs.). 



§ ' I lepidotterie e la dicogamia,' Bologna, 1888, 48 pp. See Bot. Centralbl., 

 xxxviii. (1889) p. 7'.»2. || Trans. Acad. Sci. St. Louis, v. (1888) pp. 241-77 (2 pis.). 



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