54 



SCIENCE. 



[Vol. II., No. 23. 



a. Style undeveloped in the staminate stage. 



a. The filaments rise from their original horizon- 

 tal position, place themselves against the ovary, re- 

 sume their original position, and again become erect, 

 but without lengthening; petals plane; self-pollina- 

 tion usually impossible: Buta. 



/3. The originally short, erect filaments length- 

 en, curve inwards, and again straighten; petals 

 united below in a tube; close pollination possible 

 by gravitation: Coieonema. 



b. Style developed in the stapiinate stage, though 

 not always to its full length; so placed as to oppose 

 self-pollination. 



-^ Flowers zygomorphlc. 



a. The stamens which lie on the lower lip suc- 

 cessively bend upward, and, after dehiscence, resume 

 their original position; the end of the style likewise 

 bends up at maturity : Dictamnus. 



(i. The stamens, originally bent upwards, suc- 

 cessively straighten at maturity, then bend outward; 

 the style, bent downward when young, straightens 

 when the stigma becomes receptive : Calodendron. 



= Flowers actinomorphic. The filaments suc- 

 cessively elongate after dehiscence. 



o. In the staminate stage the style is bent hori- 

 zontally across the ovary; the stamens bend over 

 the pistil successively at maturity, then lengthen, and 

 turn outward between the finally erect petals : Diosma 

 tenuifolla. 



(3. Similar to the last; but the stamhiodla, and 

 not the petals, become erect, the stamens bending 

 outward but little: Adenandra. 



y. After flowering, the style bends outward and 

 downward between the staminodia, the petals remain 

 horizontal, the staminodia lie against the ovary, and, 

 after dehiscence, the fertile stamens resume their 

 original horizontal position: Barosma. 



2. The stamens nutate but once, and simultane- 

 ously. In the staminate stage they are perpendicu- 

 lar, or incline but little toward each other, so that 

 the anthers are in contact at their margin; in the 

 pistillate stage they have bent outward. 



a. The anthers fall away when the filaments 

 curve outward : Eavenia. 



6. Anthers persistent on the bent filaments. 

 -^ Pollen may fall on the unreceptive stigma, and 

 so effect self-fertilization. Even later this is not im- 

 possible, as the wind or gravitation may carry pollen 

 from the reflexed stamens to the mature stigma. 



a. In the pistillate stage the style elongates: 

 Zieria and Eriostemon. 



(3. With normally developed stigma: Boronia 

 (ex parte). 



y. When the style lengthens, the stigma may 

 encounter the anthers of the still erect stamens: 

 ErythrocJiiton. 



= The viscidity of the pollen, and the situation of 

 the anthers, prevent self-pollination: Metrodorea. 



3. The stamens do not nutate at all. 



a. Self-pollination possible in the pendant flowers 

 after the separation of the lobes of the stigma: 

 Correa. 



6. The style is surrounded by staminodia in the 



first stage; in the second stage spontaneous pollina- 

 tion by neighboring flowers may occur if insect- 

 crossing has not been effected : Ayathosma (ex parte). 

 B. With synacmic flowers. 



1. Self-fertilization impossible. 



a. With viscid pollen: Boronia (e? parte). 



b. The stigma surpassing the anthers : Triphasia. 



2. Spontaneous self-pollination impossible because 

 of the situation of the filaments, but spontaneous 

 crossing between neighboi'ing flowers favored : Aga- 

 tkosma (ex parte). 



3. Spontaneous pollination of either sort opposed; 

 crossing by insects inevitable: Croioea. 



4. Spontaneous close fertilization possible; cross- 

 ing favored: Cusparia, Choisya, Skimmia (ex parte), 

 Murraya, Citrus. 



II. Diclinous species. 

 Self-fertilization impossible; crossing necessary: 

 Ptelea, Skimmia (ex parte). — {Jahrbuch hot. gart. 

 Berlin, ii.) w. T. [57 



zo5logy. 



MoUnsks, 



Credit to an American naturalist. — In an 

 official report by M. Bouchen-Brandely, secretary 

 of the college of France, the author states that he 

 has learned by two years of study that the sexes of 

 the Portuguese oyster are confined to separate indi- 

 viduals ; that after this discovery he conceived that 

 it might be possible to artificially fertilize the eggs of 

 this moUusk ; and that, after two years more of experi- 

 menting, this attempt has been successful. Ameri- 

 cans will be interested to learn that in 1879 ai 

 American naval officer, Lieut. Francis Winslow, 

 who was stationed at Gibraltar for a few weeks, 

 determined the unisexuality of the Portuguese oys- 

 ter, and reared it from artificially fertilized eggs. 

 His results were printed in the American naturalist 

 in 1S79 or 1880 ; but, as I have no opportunity for 

 reference at present, I cannot give the exact date. 

 — w. K. B. [58 



Notes. — In the year-book of the Verein fur 

 vaterliindische naturkunde in Wiirttemberg, published 

 lately at Stuttgart, Weinland has a paper on the mol- 

 lusk fauna of the Wiirttembergisch Franken, and 

 Wundt one on the zone of Ammonites transversarius 



in the Suabian white Jura. The second part of 



the Quarterly journal of microscopical science con- 

 tains a paper by Lankester on the existence of Spen- 

 gel's olfactory organ and of paired genit.al ducts in 



Nautilus pompilius. Heude's ' Conchyliologie 



fluviatile ' of Nanking and Central China approaches 

 completion. The ninth and concluding fasciculus 

 will appear during the present year. It is luxuri- 

 ously illustrated, and printed in large quarto. 



Kuster's continuation of Martini and Chemnitz 

 Conchylien cabinet bids fair to go on, like Tenny- 

 son's brook, forever. Lieferung 322 is announced. 

 This work would be much benefited by the total 

 exclusion of the frightful engravings which illus- 

 trated the earlier editions and are still pressed into 

 the service. J. B. 6assi(?s, known by his concho- 



