38 BOTANICAL GAZETTE [JULY 
used in the case of nut pines. Whenever possible, the material 
‘ was preserved in a mixture of corrosive sublimate and picric acid 
dissolved in 30 per cent alcohol, desilicified in hydrofluoric acid, and 
imbedded in celloidin. For rendering the sieve areas visible, hema- 
toxylin, according to EmRLIcH or especially HAIDENHAIN, proved 
useful, while a counter stain of safranin was generally employed. 
Russow’s callus reagent was occasion- 
ally of use. 
The appearances in P. Strobus will 
be first described. Fig. 1 represents in 
radial view the phloem region of a ray 
from the 6-year region of a root of a 
seedling of this age. The height of the 
erect cells is here considerably greater 
than is usually figured, for example, by 
STRASBURGER (5) and also copied in his 
Textbook (6), and such elongated cells 
are frequent in young roots. They 
‘ : suggest a close relation of these cells to 
1G. 1.—Pinus Strobus, sj . 
io a tubes, as do also the sieve areas 
which are clearly visible in this section. 
ray, showing long erect cells The cambial region of this and all the 
koe — and adouble other figures illustrating this paper lies 
Sets cases; the cam- the right. Two of the older erect 
Jal region in this and the other pesibenaencis 
figures lies to the right; X275, Cells show a doubling of the nucleus, 
(5, p. 68), is ch ae which habit, as STrRASBURGER points out 
ts “ z a : aracteristic of young sieve tubes. Immediately to 
wy OF these binucleate cells the crushed and empty older 
marginal cells are to be seen. 
Fig. 2 . : 
bvuie eat the tegion bordering on a medullary ray from an 
eua - cembroides. On the Phloem side of the cambium 
. > 0€ seen a number of prismatic cel] ‘ : 
inthe radial pi € cells arranged in several series 
radial Prane. This layer of cells is intercalated between 
Tows of sieve tubes, In ; 
visibl. ‘ some of these cells sieve plates are 
€, while the protoplasm b 
fide Gk , €comes more scanty as the older 
of the phloem is approached. | 1 
may be'seen to lose thei - In other sections such cells 
se their cytoplasm and nucleus (frequently after 


