626 Benson ojid Welsford . — The Morphology of the Ovule and 
By far the commoner condition is that of dimery. In such flowers 
both Van Tieghem and ourselves have found that the placentation may be 
obviously parietal. Diagrams from some of the sections of a complete 
transverse series are given in Text-fig. I. The two dorsal bundles which run 
straight up into the styles are obliquely 
placed and the placental bundles (v) are 
of unequal size. It is seen that only one 
placenta (i. e. the larger) bears an ovule 
(Text- fig. I. 4-5), the other is barren. 
Van Tieghem points out that the exist- 
ence of a barren placenta indicates that 
the ancestors of Juglans had produced 
more than one ovule per flower. 
By far the commonest case is that 
illustrated by Text-figs. II and III. 
In Text-fig. II we have four trans- 
verse sections at planes indicated on 
Text-fig. III. 1. These four diagrams 
(II. 1-4) show clearly that both placentae 
here contribute to the vascular supply 
of the ovule. In fact, the ovule appears 
to have become the common property 
of two placentae. This is the more 
curious as each placenta is itself supplied 
with a dual bundle (i.e. one from each 
of the two abutting margins of the 
carpels (Text-fig. III. 2). 
Another interesting point is eluci- 
dated by these sections, namely, the dis- 
the female flower, i. This is at right angles tribution and character of the packing 
to the plane of the stigmas, i.e. it is in the . /-r r TT , tw \ . 
antero-posterior plane of the flower. The tissue ( 1 CXt-tlgS. II and IV p ). 1 hlS 
horizontal hnes r, 2 , 3, 4 in dicate the planes tissue is highly transparent and is con- 
of the diagrams Text-fig. II. 1-4. 2. This & J 1 
is in the lateral plane of the flower slightly structed of series of cells running at right 
tangential, to show one of the placental 1 t of the nlarentae 
bundles formed by the union of lateral veins an g ies t0 tne SUliace OI me placentae. 
of the connate carpels. The tissue is apparently composed of a 
cb = cupule bundles, d = dorsal bundles r . . ... 
of carpel, pb = perianth bundles. v = ventral system OI COnCieSCent tricnomes which. 
bundle of carpel or placental bundle. are uniseriate and grow on until they 
abut upon the carpellary walls and more or less fuse with them. 
Nawaschin 1 describes it as follows ‘ Dieselbe fiillt die ganze Fruchtknoten- 
liohlung so voilstandig aus, dass die Oberflache der Placenta und die 
Fruchtknotenwandung sich gegenseitig berlihren und sogar stellenweise mit 
einander verschmelzen.’ 
1 Nawaschin, Ein neues Beispiel der Chalazogamie. Bot. Centralbl., 1895. 
Text-fig. III. 1 and 2. Juglans regia. 
Two diagrams from longitudinal sections of 
