302 ON THE GERMINATION OF CHaRA. 



lobes, between which it emerges into the water. At once it is divided 

 in the direction of the long axis of the oospore by a vertical walP 

 into two daughter-cells, not perceptibly different either in size or 

 shape (figs. 3, 4). Both of them grow out in the form of cylindrical 

 obtuse tubes, in which, in the hard-skinned species at least, only the 

 inner layers of the oospore membrane are continued, whilst the evi- 

 dently loosened outer layers are broken through. One of these two 

 tubes is rapidly transformed into the first pro-embryo, the principal 

 pro-embryo (fig. 2) of the future Chara plant. Beyond the divisions 

 already chiefly made known by Pringsheim, no other partition of this 

 cell ever takes place. The elongated lower cell of the principal pro- 

 embryo, so long as it exists, is bounded at its base by the primary 

 partition whose appearance gave birth to the pro-embryo. 



The other of the two similar daughter-cells of the first node in its 

 first growth resembles the pro-embryo, inasmuch as it forms an obtuse 

 cylindrical tube, and is at first undistinguishable from it ; but it soon 

 assumes all the characteristics of a root, and later on it develops into 

 the peculiar jointed and branched root of Chara. It is the first and, 

 for a long time, the biggest root of the young plant, and may there- 

 fore, in accordance with Kaulfuss's initiative, be called the principal 

 or primary root {pr.), and the half of the first node which gives rise to 

 it the primary root-cell. Of course it will be understood that this 

 appellation in no way identifies it with the radicle of phanerogams. 



At the base of the primary root- cell, that is, in the part of the first 

 node bounded by the first partition-walls, further cell-division always 

 takes place. Supposing a division of the pro-embryo and the primary 

 root, in an erect position, in the direction of the long axis of the oospore 

 to represent the plane of the principal section of the young germinating 

 plant, there are, as a rule, at the base of the primary root-cell, two 

 excentric partitions formed, in the direction of the main section, with 

 convex inner walls, so that the cell is divided into three — a middle and 

 two lateral ; the middle one being continued in the primary root, and 

 the two lateral sooner or later grow out as root-hairs. 



It was repeatedly observed, in Chara crinita, for example, that 

 the primary root began to grow before the separation of the two 

 lateral root-sources was completed ; in other, and most frequently in 

 C. fragilis and Tohjpella intricata, in all the instances noticed, the order 

 of procedure was exactly the reverse, the division first taking place, 

 then the middle cell growing out as the primary root, followed by 

 the extension of the lateral cells. So far as could be ascertained, the 

 latter are not partitioned simultaneously, but in quick succession. 

 The process- of division of the primary root-cell does not rest with the 

 3-celled body described, for there is a further increase in the number 

 of cells through the first three being again divided by partitions pre- 

 senting a convexity towards the centre, and this plan of division may 

 be several times repeated. In this way the base of the primary root- 

 cell becomes changed into a many-celled body, in which regularity in 



* It may here be observed that, in this as in all other instances of cell- 

 division in Charas, the formiition of the cellulose partition is preceded by a com- 

 plete and well-defined separation of the protoplasm of the mother-cell through- 

 out the plane of division. 



