lyo The "West American Scientist. 



They are thick and leathery to the touch and have a single central 

 rib. The green part ol the leaves sometimes become worn away, 

 especially near the ground, leaving only these central ribs or 

 stalks. The leaves are deeply notched, and in these notches the 

 flower and leaf-buds appear. The resemblance between the two 

 seems perfect, but a magnifying glass shows that the leaf-buds 

 have scolloped edges, while a flower-bud shows a single, tiny 

 point. After a few days' growth, a difference can be detected in 

 the rootlets or fibres, traceable below the buds in the leaf from 

 which they start. A leaf-bud has a single root — if that term can 

 be properly used in this connection— while a flower bud has two 

 or three. 



Six or eight weeks are usually required to bring the buds to 

 perfection, but the growth is so much modified by the temperature, 

 the degree of moisture and other conditions that no positive rule 

 can be given. The progress is for some time very slow, but 

 during the last fortnight it is surprisingly rapid. The first growth 

 is by a gradual elongation of the stem, but, at the end of three or 

 four weeks, the changes in the bud itsell become daily more per- 

 ceptible. The long, pink divisions of the calyx can no longer 

 entirely hide the greenish-white corolla, and the whole forms a 

 tightly-twisted, cone-shaped bud which gradually increases in 

 size and length. The flower-stem grows in a straight line from 

 the parent leaf until six or eight inches long, when it slowly 

 curves upward, bringing the bud into a nearly vertical position. 

 When this occurs, the blooming is likely to follow in two or three 

 days. On the morning of the last day; a careful observer can see 

 that the petals have slightly parted at the point, and this opening 

 widens a very litde during the day. 



The opening of a cereus bud is a sight to be long remembered 

 by any one who is fortunate enough to see it. Frequently the 

 bud begins to open late in the evening, but on the only plant that 

 I have had the pleasure of watching, the blooming began at six 

 o'clock. Slowly the petals separated, shaping the flower at first 

 in a form that suggested a half-opened pond-lilly. As the open- 

 ing widened, the white, filmy pistil became visible and, farther in, a 

 crowd of fine, yellow-tufted stamens. The pistil reaches the 

 entire length of the flower- stalk and can be drawn out when the 

 blossom withers. It does not stand erect in the center of the 

 flower, but lies with the stamens pressed against the lower edge 

 of the corolla. When the opening has once begun, every, 

 moment brings new and beautiful changes, and it is no exagera- 

 tion to say that one can see the flower open. More than once, 

 some one was fortunate enough to be looking at the moment when 

 a petal drew back with a visible movement Slowly the pink 

 calyx folds back or curls away from the pure, transluscent, white 

 corolla which takes a more and more beautiful shape as time 

 passes. 



