4 
I2 The Botanical Gazette. [January, — 
Fourth type, root with but one primary tissue at the vege- — 
tative point, the initial groups of all tissues being confluent, — 
or perhaps we should say possessing a common initial group — 
for all the tissues. Example, some Cucurbitacee and Papil- 
Zonace@. | 
Fifth type, roots with two primary tissues, the plerome and ~ 
periblem being distinct, and the outer layers of the cortex | 
serving the purpose of an epidermis and root-cap. To this 
type belong the gymnosperms. | 
It will be seen that the first four types pertain to angios- — 
perms and the last to gymnosperms, while the first two in- ~ 
cludes monocotyledons, and the third and fourth dicotyle-— 
dons. Hanstein and Reinke’s general type is Janczewski’s third — 
type, while the fifth type confirms Reinke and Strasburger’s 
work.on gymnosperms. 
Hegelmaier’’ from the study of embryo roots, would add 
at least two other monocotyledons to Janczewski’s first type. — 
Ss se 
appeared. Treub, from a study of the roots of monocotyle- 
Second type, but two well marked meristem tissues in the 
root, a distinct plerome and a common initial for the cortex, 
epidermis and root-cap. In this type Erickson places seve! 
Malvacee and scattered species from other groups. 
Third type, acommon origin for all the tissues, the initial of 
all the groups coalescing. This is Janczewski’s fourth type: 
SS ORS Rae SRO oA EIR a RR : 
*7Zur Entwicklung monocotyl. Keime, etc. Bot. Zeit. 1874. 
18T_e meristeme primit. de la racine dans les monocot. Leyden, 1876. 
‘Ueber das Urmeristem der Di i ir wissenscl- 
Hetin: Leipzig. 1895, icotylenwurzeln. Jahrbiicher fiir wis “ 
