338 NATURAL SCIENCE [Novenibael 
capsules. The same phenomenon was seen in Amaryllis formosis- 
sim. 
In discussing these observations Medicus writes :—“ Those plants 
which have the property of reproducing themselves by roots, especi- 
ally marked, are most unfortunate in setting seed, although no 
observer can deny the presence or completeness of the sexual organs. 
The true cause of this seems to be that these plants expend all their 
energy in increasing their roots and concentrate their nutritive 
activities on these parts, and so leave none over to contribute to 
the formation of seed. Annuals, or plants with a limited existence, 
on the contrary, for the most part, set seed, because they have little 
or no power of multiplying by their roots, which decay as soon as 
the seed is formed, and their allotted span of two to five months 
passed.” Referring again to the complete sterility of Amaryllis 
reginae, under ordinary conditions, he adds that “ scarcely, however, 
have we separated the inflorescence from its root, and laid it aside 
without moisture, than it forms large seed capsules, and clearly 
shows us that these would always be produced if the vigorous root 
formation did not rob them of all nourishment.” 
With the exception that we now regard bulbs and tubers as 
stem rather than root structures, these words have a very modern 
ring about them, and plainly show that what we now call correlation 
between the different organs of a plant was already then recognised 
by Medicus. One thing is very noticeable about his writings, and 
that is the charm of his literary style, an item which by no means 
graces too many of the scientific essays and memoirs of the present 
day. 
Medicus’ paper was written in May of 1790, and in the 
century which has elapsed since that time both Gesner’s original 
observation and Medicus’ re-discovery have been so completely for- 
gotten that in 1896 Lindemuth published an account of the same 
phenomena without any idea that it had ever been noticed before. 
Thus, as Jost’s paper in the Bot. Zeit. points out, we have here a 
fact which has three times been discovered as new, after having 
been twice completely forgotten. H. Lindemuth (Berichte der 
deutsch. Bot. Gesell., pt. 7, vol. 14), after describing precisely similar 
facts to those which Medicus had already set down, using, however, 
Lachenalia luteola and Lilium candidum as his experimental objects, 
proceeds to recount some facts which go beyond those which his 
predecessors had seen. These he embodies in a second paper, con- 
tained in the same number of the Berichte. On 25th March he cut 
off forty inflorescences of Lachenalia luteola, and placed them in 
water. About three weeks later he noticed that the lower part of 
the stem which was under water was now curiously granulated. 
Here and there a granule had become larger than its neighbours, 
