ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 641 



the course and structure of the vascular strands. The vascular tissues 

 of the "hypanth" are derived from those of the calyx, corolla, and 

 stamens ; in most of the genera the strands coming from the calyx and 

 corolla run parallel to each other and are near the surface, while those 

 from the stamens run towards the base of the " hypanth," where they 

 unite with the vascular tissues of the stem or of the " gynophores " 

 (outgrowth of axis on which each carpel is borne). In Rosa the con- 

 dition is different, for the vascular strands derived from the stamens 

 never anastomose with the other strands of the " hypanth." This 

 condition, together with other differences in the form and arrangement 

 of the vascular bundles, induces the author to disagree with those 

 writers who put the fruits of Rosa and Geum in one class. He regards 

 the fruit of Rosa as being indisputably an axis, that of the Pomaceas as 

 a combination of calyx and axis, and that of Potentilla, Primus, etc., as 

 a product of foliar origin. He concludes that in all the Rosacea?, with 

 the exception of the Pomacere and the genus Rosa, the fruit is the 

 product of congenital foliar accrescence. 



Embryo-sac of Euphorbia.* — N. Dessiatoff has studied the develop- 

 ment of the embryo-sac of Euphorbia virgata, and finds certain anomalies 

 similar to those found by J. Modilewski in E. procera. The present 

 paper is a preliminary one, and is to be followed by others dealing with 

 the same subject. The author finds that polarity begins after the first 

 division, and that in subsequent divisions a six-nuclear stage precedes 

 the eight-nuclear stage and a twelve-nuclear stage precedes the sixteen- 

 nuclear stage, owing to delay in division of some of the daughter-nuclei. 

 Not only is this another example of a Euphorbia embryo-sac having 

 sixteen nuclei, but the two lateral tetrads of nuclei form cells resembling 

 those of the normal egg-apparatus. 



Fruit of Geraniaceae.t — W. Sorensen has studied the fruits of 

 Geranium, Erodium, and Pelargonium, and is of the opinion that no 

 ordinary botanical term correctly describes them. In Geranium dis- 

 section, G.pusillum, G. molle, and G. cicutarium the ovaries are distinct 

 and no septum exists ; during maturation the carpels divide vertically 

 to the plan of symmetry into two parts, the ventral part remaining in 

 its place and the dorsal part becoming detached like a valve ; nerves or 

 hairs are constricted at the valve. In Erodium the valves do not open 

 at the lower end, but dehiscence takes place through the walls them- 

 selves. In Pelargonium the fruits resemble those of Geranium, and 

 there is evidence to show that the central column is formed from the 

 receptacle. It is thus incorrect to describe these fruits as schizocarps 

 having septifragal or septicidal dehiscence. All the above species which 

 shoot out their seeds are provided with a characteristically formed basal 

 spring. Where the seed is not shot out, the opening of the valve may 

 enlarge and allow the loose seed to be shaken out, or it may contract 

 and retain the seed, and the whole thing be distributed by the wind. 



* Ber. Deutsch. Bot. Gesell., xxix. (1911) pp. 33-9 (17 figs.). 



+ Oversigt. k. Danske Vidensk. Selsk. Forhandl., ii. (1911) pp. 99-137. 



