1 66 



THE AMERICAN MONTHLY 



[September, 



that point the fovilla appears evenly 

 distributed in the fibrilla of the con- 

 ducting tissue ; it permeates the tissue 

 of the placenta, and accompanies the 

 vascular fibre which runs through the 

 funiculus to the hilum of the ovule. 

 I have always found the ovules at- 

 tached in such a way on the funiculus 

 or raphe, or where sessile, on the 

 placenta, that their micropyle is 

 brought in easy and natural contact 

 with the fovilla carrying fibrillce or 

 papillcE of the conducting tissue. In 

 Cereus grandiflora the long funiculus 

 is covered with papillae on the ventral 

 side. 



The pollen-tube question as above 

 outlined may be brought within very 

 narrow limits ; it may be stated as 

 follows : 



Do the pollen-tubes such as they 

 are when emitted on to the stigma, 

 continue their separate existence and 

 course to the micropyle of the ovules 

 under the guidance and nurture of the 

 conducting tissue ? 



Or do the pollen-tubes discharge 

 their contents amongst the papillae of 

 the stigma, which is the aggregate head 

 of the librillae of the conducting tissue 

 of the style ; thus carrying down the 

 substance of the pollen only, to the 

 ovary as an entirety, so that when- 

 ever the papilla, around the micropyle 

 of the ovule, come in contact with the 

 conducting tissue and its fibrillae, the 

 ovule is fertilized by absorbing the 

 substance of the pollen-grain ? 



Thus according to one theory the 

 functions of the conducting tissue 

 would be to conduct the pollen-tubes 

 to the ovary, whilst according to the 

 other, the conducting tissue would only 

 serve as a vehicle to carry the sub- 

 stance of the pollen to the same desti- 

 nation. 



What I stated above on the distribu- 

 tion of the fovilla in the conducting 

 tissue is shown in sections of the ovary 

 of Cereus gt-atidijlora. 



It would puzzle an observer greatly 

 to trace the course of the pollen- 

 tubes from the sessile stigma of 

 the poppy (if sucb exist, I have not 



been able to discover any; in fact, only 

 on a comparatively small number of 

 plants are pollen-tubes visible on the 

 stigma) down to the many parietal 

 divisions of the ovary. A transverse 

 section reveals, however, the modus 

 operandi and the distribution of the 

 bundles of the conducting tissue. The 

 papillae on the rays of the stigma cor- 

 respond with as many bundles of con- 

 ducting tissue which descend in the 

 wall of the ovarian capsule to the 

 base of each parietal division where 

 they appear as a loose net-work on the 

 back of the placentary surfaces, both 

 of which are beset with numerous 

 ovules. 



A Microscopist Kambliiig. 



One Sunday morning, in August, 

 bright and clear, the writer was in 

 Birkenhead, which is situated op- 

 posite Liverpool, across the river Mer- 

 sey. Starting out aimlessly, more in 

 search of change and rest than with 

 any other end in view, it was a ques- 

 tion whether to climb the hill upon 

 which the celebrated Bidston obser- 

 vatory is situated, from whence could 

 be seen the river widening into the 

 broad bay, and the stretch of water 

 bounding the horizon beyond ; or to 

 take the opposite direction, cross the 

 ferry to Liverpool, and there look for 

 a means to reach a secluded spot with 

 fresh air, and freedom from the noise 

 and travel of the city. The latter 

 course being chosen, we were soon 

 on the other side, and, not caring to 

 go up into the city if a boat could be 

 fountl running to a sandy beach some- 

 where near by, we did not leave the 

 docks, but sauntered along the river 

 where theie was little observance of 

 the day. Excursion-boats were await- 

 ing the time of departure, and rapidly 

 filling with people ; steam-tenders 

 were delivering cargoes of live-stock, 

 cattle, sheep and pigs, and it was 

 amusing to watch the serious, systema- 

 tic method of an elderly person from 

 the Emerald Isle who was counting 

 his sheep as they passed before him, 



