7 1 8 Thomas. — Seedling Anatomy of 
Lunar ia biennis is of interest on account of the very different habit of 
the seedling with its comparatively large thick cotyledons. The base 
of the cotyledons shows in addition 
to the central double strand a small 
lateral on each side. These maintain 
their independence above the cotyle- 
donary node, indeed in some cases 
may be said to pass into the hypo- 
cotyl independently. There are no 
differentiated plumular strands as in 
Aethionema , &c., although the pre- 
sence of a robust cambium and the 
half-obliterated condition of the proto- 
Text-figs. 29, 30. 29, Lunar ia btenms. X ylem show that the seedling is past 
| nat. size. 30. Outline of cotyledonary node ~ . 
of same. the primary stage. The most notice- 
able feature of the transition is the 
presence of four phloem groups throughout the hypocotyl arranged so as to 
form two elongated bands of phloem, the middle of which is probably 
chiefly secondary. 
Lunar ia annua is described by Chauveaud 1 as showing free laterals in 
the upper part of the hypocotyl. 
Cardamine hirsuta seems to be quite normal, but only a rather old 
stage has been examined. 
Barbarea vulgaris. It is interesting to note in this form, which is 
placed by Engler not far from Lunar ia, that there seems to be the same 
somewhat leisurely manner of completing root structure, although the habit 
of the seedling is quite different and laterals are not found so low. It 
differs from Lunar ia in the presence of a strand already lignified in the 
hypocotyl, which corresponds to the midrib of the first leaf. In Bismarck 
brown and gentian violet preparations the red-brown half-obliterated 
protoxylem elements, which are quite exarch in the cotyledonary node, 
present a marked contrast to the brilliant blue of the later-formed xylem 
elements. 
Crambe tartarica differs from the other members of the Cruciferae 
examined in the wide separation of the halves of the double bundle in the 
hypocotyl. The laterals are free near the base of the cotyledon, and as in 
Lunaria may enter the hypocotyl independently. 
Chauveaud 2 reports lateral strands in the hypocotyl of Brassica 
oleracea , and at the base of the cotyledons in Ricotia lunaria. 
Raphanus saliva is the species in which Chauveaud 3 first observed 
‘ resorption’ of protoxylem. 
1 Loc. cit, 1911. 2 Loc. cit, 1911. 
3 Chauveaud, G. : Compt. Rend. Acad, des Sc., 1901. 
30 
