EDITORIALS. 
IN THE PREFACE to the second edition of his Survival of the unlike, 
Professor L. H. Bailey explains his adoption of the idea of the phyton 
as a unit of plant structure and function, to which in a 
Is the Phyton review of the first edition* we took exception, asking 
a Concept of whether the idea of the shoot would not answer the pur- 
any Value? pose better, since the variations to which he called 
attention existed not so much in the successive phytons 
as in the shoot taken as a whole. We quote his words of reply in 
order to examine further his conception of the phyton: 
Itis by no means essential to the conception of the phyton that the different 
phytons upon any branch shall be unlike; although it should be remembered that, as a 
matter of fact, no two branches on a plant are alike, and yet every branch springs 
from a phyton. The point is that any phyton is capable of making a new plant, and 
the characters of that new plant will be very markedly determined by the conditions 
under which it grows. The phyton is simply the unit of asexual propagation as the 
seed is of sexual propagation. (See the contrasts of the Aezme and the Awospen in 
Mobius’ recent Beitrige zur Lehre von der Fortpflanzung der Gewdchse.) 
The word bud might be substituted for phyton, but that word now has two or 
three technical uses; and, moreover, it is not always necessary that actual buds be 
Power, when removed and properly cared for, of expanding into what we call a plant, 
and of perfecting flowers and seeds and of multiplying its kind (p. 83). 
THE HISTORY of the theory of the phyton is that of every other 
discarded theory. Its form is first modified; then it is remodeled 
again and again in the hope of making it fit the facts better, until — 
finally it is apparent that it must be entirely abandoned for something 
better. Gaudichaud brought the phyton into prominence, basing the 
theory upon the anatomical vagaries of Wolff and Du Petit Thouars. 
But a fuller knowledge of anatomy through the researches of von 
Mohl led to the general abandonment of the concept in the form in 
which he advocated it. Dr. Gray adopted the idea in a modified form, 
retaining the term phyton, and was the first to introduce it authorita- 
2 ©} Ror. Gaz oa: sa1..D. 1896. ae ae. 
: 1897] a7 
