PROCEEDINGS OF SOCIETIES. 19 



exactly as described by Unger, the fructification progressed towards its develope- 

 ment, the granular matter continuing to become more dense and opaque, and in its 

 structure numbers of comparatively clearer spaces formed, which increasing, at last 

 showed the capsule filled with from twenty to fifty zoospores arranged like the meshes 

 of a network, and having still some granular matter evident at the sides of the cap- 

 sules. I then distinctly noticed a movement of the four anterior zoospores (this I 

 wish to state distinctly, us I find that Alexander Braun, whose accuracy of ob«er- 

 TatioQ is so well known, states that in ^^ Derbesia, Saprolegnia and Chytridium the 

 motion'* which commonly occurs in other families, '' does not become evident until 

 after birth of the previously crowded germ cells*' — I have also been able to verify this 

 movement more than once) previous to their escape from the mother cell, one of 

 them applying itself to the flask-like orifice, and gradually* forcing its way out ; evi- 

 dently, as sketched, undergoing considerable pressure in tne process, which probably, 

 in this instance, occupied half an hour. Its escape was soon followed by that of the 

 other zoospores, generally emerging two by two, one succeeding the other with grea( 

 rapidity, and darting out for some distance (at least half the length of the capsule) 

 into the water ; they then, after a short rest, floated off right and left with evident 

 motive power, and tlie other cells in the capsule in their turn began to exhibit inde- 

 pendent movements and to escape ; finally, the entire got out, leaving the capsule 

 empty, the process taking altogether half an hour or a little longer for its completion. 

 Almost all the zoospores that 1 observed resumed their globular form soon after escap- 

 ing, and ceased to display motile force in the course of six to ten minutes, after which 

 they became stationary. To illustrate the rapidity of the formation of these cap- 

 sules, I may mention that a tuft of barren tubuli, removed late at night and placed 

 for observation in a glass cell, had developed its fructification in great luxuriance by 

 next morning (within twelve hours), and from this I obtained the varieties of globu- 

 lar mother cells, and those with double and triple cells, and also those remarkable 

 monstrous forms in which the barren tube grows again above the apex of the capsule. 

 Some of the barren tubes grew to a very great size and thickness, and developed 

 spores within their substance ; this, however, was extremely rare. I also saw such 

 a tube emit four spores from its extremity, but they displayed little motile power, 

 and floated ofl* only a short distance after their escape. I cannot decide as to these 

 spores having cilia. Thurot describes their having two, Alex. Braun found only one 

 single short cilium. I did not succeed in getting them ; probably I might with 

 higher powers of the plant. It is, perhaps, too often assumed that cilia are indis- 

 pensable for producing motion in cells. I obtained very perfect views of the mode 

 of propagation of the spores. Many of them multiplied by a process of gemmation 

 exactly like the cells of yeast; and the freshly-formed cell might by observation be 

 seen with its fine granular contents aggregating together and forming large masses, 

 and even transparent glistening globules of oil. So rapid was this budding process 

 that the same parent cell had occasionally two, three, and four buds derived from 

 the various parts of its surface and in diff*erent states of development. As they ac- 

 quired a bulk nearly equal to that of the parent cell, I could generally observe the 

 formation of a division occurring between the two; and this rapid production of 

 cells soon formed dense masses of vegetation, which by a little care could be seen 

 growing under the microscope. I would wish to direct attention to a very interest- 

 ing mode of development which I have procured sketches of — the formation of thin 

 hair-like shoots proceeding from a parent cell, and at its extremity the reproduction 

 of the cell-form again resumed, in its usual condition prepared for active fissile de- 

 velopment. I would merely state, in connection with this, that the growth of some 

 forms of mould appears to be closely analogous to what I have described. Thus, I 

 have seen similar thread-like processes connecting the sporules of the Ascophora 

 Mucedo, and it api)ears to me to be both an indication of extreme vital energy in 

 the reproductive process and also an arrangement, the object of which is evident, to 

 enable the spores in their development to spread more rapidly over a more extended 

 surface, and to interfere less with each other in their mutual growth. Having thus 

 obtained a second condition of this plant, in which it is a rapidly budding unicellular 

 body, I watched with much care for its return to the tubular form, and was able to 

 trace it pretty perfectly. As the masses of cells developed they became rather larger 

 in bulk and loss defined (their utricle or limiting membrane) if at all existing, being 



