490 WEATHERWAX: SPIKELETS OF ZEA Mays 
The ‘‘silk,” which is peculiar to maize and teosinte, probably 
owes its unusual structure and exceptional length to the presence 
of the husks that cover the inflorescence. The writer has pre- 
viously called this organ a stigma. Since the use of this term has 
been questioned, a further statement seems appropriate here. 
The difficulty seems to 
lie in finding a consistent 
and generally accepted 
definition of the word, 
stigma. Some. writers, as 
Strasburger and a number 
of his students, speak of it 
as a morphological unit of 
the pistil, codrdinate with 
the style and the ovary; 
and others define it as merely that portion of the surface of the 
style upon which pollen grains may germinate. In dealing with the 
grasses it is convenient to speak of the feathery part of the filament 
extending upward from the ovary as the stigma and of the smooth 
part as the style. Strasburger makes this distinction in his text 
book. Many other writers, in describing the grasses, recognize 
the convenience of such a distinction when they speak of the 
“two or three feathery stigmas.” It was not, and is not now, 
the writer’s intention to form a new definition of terms. The 
point intended is merely this: The corn silk, being compound in 
structure and plumose and receptive to its base, is the homologue 
of the ‘‘two feathery stigmas” of other grasses. If the common use 
of the word, stigma, in speaking of other grasses is inadvisable, and 
a consistent nomenclature is devised, the appropriate use of the 
word, style, for the corn silk is conceded. 
From the very beginning (PLATE 23, FIG. 3) the silk is divided 
at the tip, and this division continues into the mature structure, 
which has already been described (8, p. 133). Two strands of 
vascular tissue traverse the entire length of the organ (TEXT-FIG. 
16). Neither in transverse nor in longitudinal section is there 
any evidence of a tissue morphologically differentiated for the 
passage of the pollen tube, as has been described for other grasses. 
The plumose appearance of the stigma is due to numerous 
