THE GENERAL MORPHOLOGY OF THE PLANT. 



(28), in the liquid which fills the body of the mother-cell : these, 

 escaping when that decays or bursts, grow into similar plants, in 

 the manner shown by Fig. 67 - 69. 



99. The new cells by which Vaucheria is propagated are pro- 

 duced in a different way ; as is shown in V. clavata (Fig. 71, 72). 

 The apex of a branch enlarges ; its green contents thicken, sep- 

 arate from those below, and a membrane of cellulose is formed 

 around it, just as it forms around the contents of the whole cell in 

 the microscopic Chroococcus (Fig. 63), but no further division takes 

 place ; the wall of tire mother-cell bursts open, and the new-born 

 cell escapes into the water. When it grows, it elongates a little 

 from one end, and by this fastens itself to any solid body it rests 

 on, and then grows from the opposite end into a prolonged tube, 

 with occasional branches, like its parent. In this way, a plant 

 composed of a single cell imitates not obscurely the downward and 

 upward growth (the root and stem) of the more perfect plants. In 

 the foregoing cases we noticed that the production of new cells in- 

 sured the death of the parent; the whole living contents being ap- 

 propriated to the new formation. In this case, the progeny origi- 

 nates from the living contents of a part of the cell only, and the 

 walls of that portion alone perish. 



100. Plants of a Single Row of Cells, To these there is but a sin- 

 gle step from plants formed of a single cell (whether branching or 

 unbranched) which has the power of continuous growth from the 

 apex ; and that step consists in the formation of transverse parti- 

 tions. The man- 

 ner in which these 

 are produced has 

 been already de- 

 scribed (Fig. 8), as 

 observed in a spe- 

 cies of Conferva. 

 Most of these sim- 

 ple, thread-like Al- 

 gae are composed 

 of a single row of 



cells, produced in this way. The three" kinds of Moulds or Mil- 

 dew Fungi here represented (Fig. 74-76) consist, as to the 



FIG. 74. The Bread-mould (Mucor) magnified. 75. Another Mould (Penicillum glaucum). 

 76. Botrytis Bassiana, a parasitic Mould : all magnified. 



