J 12 FREAKS OF PLANT LIFE. 



" The glands vary very much in size, and are 

 composed of five or six layers of thin-walled cells, 

 without intercellular spaces. The cells of the super- 

 ficial layer have their longest diameter at right angles 

 to the surface, those of the next layer are about 

 equal in all directions, while those beneath are 

 flattened in all horizontally, and have walls of ex- 

 treme thinness. At the base of the gland are gene- 

 rally to be seen one or two spirally-marked cells, in 

 a group of which the vascular twig always terminates.'' ^ 



Dr. Lawson Tait constructed an elaborate table, 

 in which are shown the variations in size of the 

 glands found in the pitchers of one species. Pro- 

 gressing downwards, from the opening to the bottom 

 of the pitcher, the glands were measured at every 

 five millimetres, commencing in size at '045, and 

 gradually increasing until they attained a diameter 

 of "2 mm. Through the whole course downwards an 

 increase was maintained, which was gradual for the 

 first third of the distance, then suddenly the diameter 

 is almost doubled. During the second third of the 

 course the diameter is increased about one-third, 

 whilst in the last third the increase is very slight. 

 The estimated number of glands in a square milli- 

 metre are "j^ in the upper zone, 25 in the middle 



• W. H. Gilburt in " Journal of Quekett Microscopical Club,^ 

 vl., p. 162. 



