14 Rev. W, A. Leighton on Acacia magnifica. 



iodine produced no change of colour in any of these parts. On 

 moistening the section with water, the external lips of the orifice 

 become swollen and partially closed, the slit alone being visible, 

 as seen, more highly magnified, in fig. 4 (where the same letters 

 indicate the same parts as in fig. 3, viz. d, epidermis ; e, chloro- 

 phyll-cells ; /, loose white cellular tissue ; g, dense white cellular 

 tissue ; h, dense yellow cellular tissue ; i, glandular slit ; k, bun- 

 dles of vascular and spiral vessels). Here it is seen that the 

 epidermis ceases somewhat above the base of the slit, where 

 apparently the cellular tissue is exposed, and from which surface 

 the pellucid liquid is excreted. 



The plant began to blossom on the 27th of March, and was 

 then removed from the green-house into the drawing-room, 

 where the secretion immediately attracted my attention. I my- 

 self watered the plant every morning ; and thus it was daily, and, 

 indeed, many times every day, under my constant observation ; 

 and the secretion was pointed out to members of my family and 

 to many friends almost daily. As I proposed to investigate the 

 source and cause of the secretion with the microscope, I carefully 

 watched it day by day, and am thus able to state definitely that 

 the liquid drop was visible on the upper edge of every phyllodium 

 subtending a spike of flowers during the whole time the plant 

 continued in flower, viz. from March 27 to April 22. For a few 

 days previous to April 22, the secretion appeared to decrease 

 and partially to cease on some of the phyllodia. On April 23 

 the blossoms began to wither and fall. On the 24th the blos- 

 soms fell moi-e rapidly and abundantly ; and, to my surprise, 

 there was an almost total cessation of the secretion, which now 

 appeared on a veiy few only of the phyllodia. On the 24th the 

 plant was returned to the greenhouse, and since that day to the 

 present time (May 30), although the plant has been watched 

 carefully for this express purpose, not the least secretion has 

 taken place, and the orifice of the gland appears to have become 

 partially filled up or obliterated. 



Here observation ends; but, on beholding such a curious 

 structure, the mind naturally speculates — but in vain — How is 

 this seci'etion eflfected ? Nature does not disclose her vital forces. 

 We then turn to the probable end to be efi'ected by such a pro- 

 vision; and here conjecture may be possibly more successful. 

 The secretion takes place only during the period that the plant 

 is in blossom. So soon as the flowers fade and begin to fall, 

 the secretion ceases and disappears. It would seem then to be 

 in some way or other connected with the fertilization of the 

 flower; and as, when the secretion becomes excessive, it falls 

 and blotches the lateral expansion of the phyllodium, it is pro- 

 bably to attract insects to efi^ect this. It is right, however, to 



