25 



elongated cells exhibit are very remarkable series of changes, which 

 Mr. Henfrey regards as differing from anything that has yet been 

 observed in analogous structures. They are at first killed, like the 

 elaters, with a delicate colourless protoplasm, in which float exceed- 

 ingly minute granules, and which is apparently the same substance 

 that occurs in all young cells which increase by self-division. These 

 larger cells soon exhibit transverse streaks of a lighter colour, in con- 

 sequence of the separation of the protoplasm into a number of distinct 

 portions, and the formation of cross membranes at these places, dividing 

 the tubular cell into a row of cells, all of a square form, except the two 

 terminal ones, which are attenuated towards the free point. The author 

 could not determine whether the septa were formed by gradual growing 

 in of the membrane, nor could he detect at this period a double 

 membrane, which must, however, exist, to admit of the subsequent 

 separation of the contained cell. Vertical septa are often formed in 

 addition, producing a double row of cells within the tube. About 

 the time when the cells separate from each other, their contents 

 imdergo a change, which exactly resembles that which occurs in the 

 contents of the parent-cells and special-parent-cells of pollen when 

 the formation of free cells is about to take place in their interior. 

 The mucilaginous matter, or protoplasm, acquires a deep yellow 

 colour, becomes much thicker, and exhibits a quantity of globular 

 bodies which look like drops of oil. Mr. Henfrey gives his reasons 

 for regarding these appearances neither as drops of oil nor as vesicular 

 cavities, but as globular drops of the yellow protoplasm. Such glo- 

 bules are of various sizes and sometimes occupy half the cavity of the 

 cell, but neither before nor after their formation was the author enabled 

 to detect the presence of nuclei. 



Soon after the separation of these cells their yellow contents exhibit 

 lighter streaks running across, which denote that they are each about 

 to separate into four portions. When these portions are completely 

 isolated and become coated by their proper membranes, they consti- 

 tute the spores, and are subsequently set free by the solution of the 

 membrane of the parent-cells. Their contents then again become 

 clear and almost colourless, their membrane becomes thickened and 

 of a bright yellow colour, and finally their cavity becomes filled with 

 globules of pretty regular size. No trace of septa dividing the parent- 

 cells into chambers, such as are met with in the special-parent-cells 

 of the pollen, were observed, even when treated with iodine ; and 

 when the parent-cells in which the contents had parted into four 

 portions were ruptured at one place, all the contents passed out and 



Vol. IV. E 



