11 



in about a week ; the lowest one taking the lead. By the 16th of July 

 all bloom had fallen from the umbels. The seed was well set on the 

 terminal or axial umber, but not so on the lateral ones. The umbels were 

 now all suddenly stricken by aphides and thickly beset by them ; the 

 development of tlie seed of the lateral umbels was checked. The 

 aphides began to appear on the 12th. 



The outer rays of central umbel now measure from 9^ to 10^ inches. 



The outer rays of the three central umbels below measure from 6 to 

 f)^ inches. 



The outer rays of the lowest lateral umbel measure from 7 to 6| 

 inches. 



The central umbel has 64 rays and its diameter is 19 inches. 



The diameter of the lateral umbels, with slight variations, is 15 

 inches. On the 1 7th of July the central umbel, with 7^ inches of stalk, 

 was cut off, and was found to weigh 1-lb. 3-oz.* avoirdupois, the seed 

 was fully formed. 



When the umbel wa? thoroughly dry and seed beginning to fall off, 

 (the 1 3th of September, ) the umbellules were removed and the seed of 

 each separately examined ; such as was shrivelled, undeveloped, and 

 without vitta, or insect-eaten whilst waiting to be counted, was reckoned 

 as defective or abortive, the rest as fair. The general amount of seed on 

 an umbellule varied from 85 to 31, the abortive from 14 to 21. The 

 total amount was 3,230 seeds, of which 352 were defective or abortive, 

 leaving 2,878 as fair seed. At the end of three months, the seed being 

 thoroughly dry, the whole quantity of fair seed was weighed in 40-grain 

 parcels, giving a total of 688 grains. 



Com2)ari8on icith plants of parent-stock. 



In order to compare the plant under observation, which had grown 

 under some disadvantages, with another better placed, a strong and healthy 

 specimen was sought for in the ground whence this one had been 

 transplanted. Many fine plants bloomed on that ground year after year 

 for 20 years ; the aspect was well open to the S., but was closed on the 

 N. side by a high gaol wall with shrubs at the base, amidst which the 

 plants grew. Plants in all stages of growth, according to their season, 

 were growing under and in front of the shrubs. Several of the larger 

 plants in bloom had four umbels arising together from the first node below 

 the central umbel, the stalks of a few of these had small umbels springing 

 from thom at the positions where the stipulate bodies were noticed in the 

 transplanted specimen, thus forming a third series of blooms, but their con- 

 dition did not promise the formation of good seed. Host of the flowering 

 plants varied in height fi'om 7 to 8 feet. The tallest one was selected for 

 spicial observation, it was bent down by its top weight as some of the 

 others were, to an oblique direction. The measurement of the stem from 



• Some of the aphides remaining on umbel may have influenced the oz. 



