86 



OBNERAL REVIEW OF THE ORC'HmE.E. 



mass that quite filled up the stigmatic eavity. On examination under 

 the microscope the pollinia were found lo lie l>i'('aking up into groups, 

 generally of four granules, from some of wliicli short tubes liad already 

 protruded. Four of tlu'sc groui)S as seen uihIit the highest power at 

 our disposal (that is, magnified 250 times) arc shown in Fig. ^. 

 After a further interval of six days tlie Horal segments had hecome 

 quite withered, the epidermis of the column liad hecome dull purple 

 along the ridge, the tubes emitted from tl:e pollen granules had 

 increased immensely in numbers, and the foremost could be traced 

 as far as the base of tlie column. Fig. 6 represents roughly the state of 

 affairs at this epoch ; the polleu-tulies as observed under a magnifying 

 power of about 75 diameters are here seen passing downwards in vast 

 numbers among the elongated cells of the conducting tissues. 



The changes that take place in the ovary during the 

 first month after the pollination of the flower are shown 

 in Fig. 7 by transverse sections natural size in three 

 different and successive stages of development, A at time 

 of pollination, B a fortnight later. The change of form 

 that had taken place in this short interval is -^-ery 

 striking ; the outline had changed from the circular to 

 the triangular ; the simple sunk lines of the earlier stage 

 had widened into wedge-shaped clefts, dividing the whole 

 into three well-marked carpellary lobes ; each lobe had 

 attained an almost triangular form by the enlargement 

 of the placenta, and by the thickening of the walls of 

 Fie. 7. the ovary itself ; C shows the further development at 



tlu! (^id of the month ; the placenta and rudimentary ovules had then 

 began to show a more definite form although no signs of impregnation 

 of the latter could be detected. On the day section C was made, the 

 pollen-tubes were found to have entered the ovary, and were pushing 

 downwards along the sides of the placentas and among the ovules. 



The condition of the rudimentary ovules 

 themselves at this date is shown in 

 Fig. 8, which is an enlarged view of 

 a minute section ; they were as the 

 figure shows grouped in clusters of no 

 /civ!;', very definite form and outline ; each 

 ovule has the appearance of a single 

 cell, but so minute are they at this 

 stage that no differentiation of parts 

 could be made out under the low 

 microscopic power to which we were 

 restricted, although a faint reticulation 

 was observable in some of the most 

 J. J g advairced. 



