26 Linnean Society. [March 19, 



quently divided by transverse partitions or diaphragms. The cells 

 which form these partitions are curiously arranged — they are flat- 

 tened on t^o opposite sides, and connected vrith each other by their 

 narrow sides and extremities, but only at intervals, so that tl\ere are 

 numerous holes formed which afford a free communication between 

 all the channels. In the partitions of the root the intervening holes 

 are so large in proportion to the breadth of the cells that these have 

 the appearance of a string of beads. Another peculiarity of the 

 root is, that, in addition to the diaphragms formed of this tissue, 

 which are also found in the stem and leaf, a peculiar body is fre- 

 quently met with occupying a similar position to the diaphragms. 

 These bodies (for they are sometimes numerous) are each formed of 

 one or more cylindrical cells coiled up in a gyrate manner. They 

 grow from the angle formed by the partition and the cuticle, and 

 are developed subsequent to the other tissue, for they may be found 

 in various stages of advancement in the same root. Their nature I 

 have not been able to ascertain. 



The author then proceeds to describe the development of the spo- 

 rules. A transverse section of the involucrum when about the size 

 of a small pin's head shows it to consist of four integuments, con- 

 tainins' a mass of very delicate spongy compressible cellular tissue, 

 subdivided into four equal triangular portions by four lines radiating 

 from the centre. In the centre of each of these portions is a cavity, 

 and projecting into each of these cavities are a number of nipple- 

 like processes which are attached in each cavity to a common recep- 

 tacle, whUst this again is connected with an open rigid cellular 

 tissue that lies between the spongy tissue before described and the 

 involucrum, and serves as a connexion between the two. As the 

 involucrum advances, the spongy tissue recedes all round the four 

 cavities, which consequently become larger and afford more space 

 for the growth of the nipple-like processes. This recession of the 

 spongy tissue is not caused by the pressure of the growing pro- 

 cesses, for it is frequentiy in advance of them ; but it is produced by 

 a gradual condensation inherent to the tissue around the cavities 

 and along the radiating dividing lines, which, in fact, are nothing 

 more than this condensation, which at maturity is so complete that 

 the whole of the spongy tissue is condensed into four dissepiments, 

 dividing the cavity of the involucrum into four equal loculi. The 

 nipple-like processes are found upon a careful examination to be 

 hollow sacs with obscurely cellular walls — those which occupy the 

 lowest part of the involucrum being considerably in advance of the 

 upper ones. These sacs contain a quantity of grumous matter, and 



