On u Fasciation." 
7 * 
plurality of parts, or “ positive dedoublement,” which is the 
older of the two. None of the structures coming under 
this head can be the result of either of those two tendencies 
acting alone, for they are clearly intermediate in character between 
the two sets of structures, which I have described under I. and II. 
If the principle be clearly understood it is seen to shed a bright light 
upon these otherwise weird, inexplicable phenomena of “ fasciation” 
or “ banding ” ; it may be termed (1) the ideal or morphological 
explanation thereof, and is, to my mind, by far the most important 
of the three sets of causes to be mentioned. The structure at birth 
exhibits the influence of tendency I., viz. : that of “ negative 
dedoublement”; later in life the influence of tendency II., viz.: that 
of “ positive dedoublement,” appears upon the scene; hence giving to 
the structure two distinctive characters whereby it exhibits in its 
lower and older region fusion, in its upper and younger region 
branching or separation. Hence in the development of an ordinary 
“ fasciated ” shoot we have precisely the same phenomenon 
presented to us as in that of a staminal group in a flower, e.g. of 
Hypericum ! 
Let us now consider (2) the mechanical or real cause of the 
phenomenon. It was my own opinion that the fasciated organ 
represents in itself from birth onwards the equivalent of two or more 
organs of which at the earliest stage there was absolutely no sign, 
and that, owing to the inherent tendency for these latent organs 
(if I may so term them) to assert themselves, the subsequent 
branching gradually (as shewn in the case of shoots by the 
appearance of furrows and ridges and a strap-shaped expansion of 
the organ) ensued. I am indebted to Dr. A. H. Church, of Oxford, 
for the more concrete and definite concept of “ growth-centres.” 
He says that in the normal shoot “growth is distributed at the apex 
of a shoot in such a manner that its transverse-component may be 
expressed by a plane circular construction around a central point 
(the growth-centre ),” and “ that the circular section of the vast 
majority of plant-axes is evidently the outcome of such a regular 
and symmetrical distribution from the ‘growing-point’ ” The 
three exceptional cases he cites are (1) the cladode, (2) the fasciated 
stem, and (3) the dorsiventral shoot. I am here only concerned 
with (2), which Church explains as follows: “In the ‘fasciated’ 
system, the centric distribution around a point (the single growth- 
centre) is changed for an attempt at similar distribution around a 
number of such centres (cf. monstrous flowers of the Buttercup 
with two or three gyncecial cones, and double Daffodils) or around 
