226 HYDRODICTYONE^. 



issuing from the interior of the membrane in which it was 

 contained, and which, without doubt, was open for the pur- 

 pose of its escape * ; and after this separation it floated on the 

 water under the form of a cylindrical cell. Soon it flattened 

 itself, and underwent an alteration, which I would com- 

 pare to that which the beginning of fusion produces upon 

 metals ; then it increased gradually in every direction, and, 

 the reticulations being cleared the one from the other, be- 

 came itself a new network, which one might distinguish 

 with the microscope. Soon the reticulations were to be seen 

 with the unaided sight, and at last each cell (or division of 

 the pentagon), was totally changed into a network entirely 

 like to that of which it made part. All these transformations 

 took place in the space of a few days, and at the end of two 

 or three months the young reticulated productions had acquired 



the full dimensions of wliich they were capable 



We have here then an example of reproduction more re- 

 markable perhaps than those heretofore observed." 



" In conclusion, there is but little room to doubt that if the 

 sides of the reticulations of the network of the preceding 

 year be the networks of this year, the sides of the reticulations 

 of the present networks will also be the networks of the next 

 year, that each cell or fibre of the reticulations is itself the 

 network which shall develope itself on the second year, and 

 that the fibrilla of the principal fibre will be the network 

 which shall develope itself on the next year, and so on until 

 it please the Author of Nature to put an end to this deve- 

 lopement by destroying the species which presents it." 



* Aresclioug, wlio has published an excellent paper in Schlechtendars 

 " Linnaea," for 1842, on the mode of growth q'l Hydrodictyon utricidatiim^ 

 states that he has never been able to detect in this plant the enclosing 

 tube. Dr. Areschoug has made the interesting discovery of the exact 

 mode of formation of the minute network, viz., by the union of the 

 numerous spores while in the parent cell, previously to which they are 

 observed to be in lively motion ; the parent cell itself is absorbed, and 

 thus the new plant is eliminated according to Areschoug. 



