406 XXIX. THE GYNCECIUM OF ANGIOSPERMS. 



and bears flowers the whole year round. It is remarkable in 

 that its embryo-sac grows upwards into the micropyle, and hence 

 the whole egg-apparatus appears without any other covering than 

 the wall of the embryo-sac. Cross-sections through the free, 

 elongated ovary show this to be two -celled ; the two axile pla- 

 centae project as pads into the loculi. They are covered with 

 numerous ovules. For the purpose of their study we remove a 

 part of the wall of the ovary, and strip off the ovules -from the 

 placenta, preferably under the simple microscope. We observe 

 them with advantage in a 3 per cent, solution of sugar. The 

 ovules are anatropous, or, more correctly, somewhat campylo- 

 tropous, for the embryo-sac and the integument are bent in their 

 upper part (Fig. 148, A). The free part of the funicle (/) of the 

 ovule is pretty long ; only one thick integument is present. The 

 embryo-sac (e) projects with its upper end out of the micropyle. 

 This protruding part is swollen and pointed at its apex ; it lies 

 against the funicle. It is difficult to follow the embryo-sac in the 

 interior of the ovule, but by running in a little potash we can, at 

 the beginning of its action, convince ourselves that it immediately 

 impinges on the ovular integument, is first very narrow, then 

 swells somewhat spindle-shaped, and (e*) again narrows at the 

 base. Our preparations in sugar solution show, in the free apex 

 of the embryo-sac, the two synergidae and the oosphere ; once 

 more therefore, as always, three cells form the egg-apparatus. 

 According to the position of the preparation two synergidae are to 

 be seen (Fig. 148, B), or one conceals the other (C). At the apex 

 of each synergida we notice a homogeneous, strongly-refractive 

 cap, sharply defined against the finely granular portion behind ; 

 this is the so-called filiform apparatus. If such a preparation is 

 treated with chlorzinc iodine, the caps of the synergidae are seen 

 to colour blue. They consist therefore of cellulose. The rest of 

 the substance of the synergidae and of the oosphere colours yellow- 

 brown. Careful examination shows that the membrane of the 

 embryo-sac is open over the caps of the synergidae (B, C). The 

 filiform apparatus therefore forms a stopper in the opening of the 

 embryo-sac. This apparatus is very widely distributed, especially 

 amongst monocotyledonous plants, and projects often very far out 

 of the embryo-sac. The longitudinal striation, often observable, 

 arises from fine pores filled with protoplasmic contents. We 

 return to our preparation lying in water or in sugar solution, and 

 determine that the distribution of contents in the synergidae and 



