732 Some remarks on the development of Pollen. [Nov. 



VI. — Some remarks on the development of Pollen. By William Grif- 

 fith, Assistant Surgeon, Madras Establishment. 



Pollen of Pardanthus Chinensis, Ker. Nat. Order Iridece. 



At the earliest period submitted to examination, and when the 

 perianth scarcely exceeds half a line in length, the anthers are sessile 

 and nearly perfectly formed. The cells, of which (as is perhaps the 

 case in all bilocular anthers) there are four, contain a solid grumous 

 semi-opaque mass, which is easily detached from the cell by slight 

 pressure. This mass under a lens whose focal distance is one-twen- 

 tieth of an inch, shews evident traces of cellularity, but the outlines 

 of the cells are very faint. They are entirely filled with exceedingly 

 minute granular matter. At a somewhat later period the cellularity 

 of the mass is more obvious, but no separation of the component parts 

 has taken place, and the cells are still entirely occupied by the granular 

 matter. 



When the perianth has attained the length of a line and a half, the 

 mass will be found to have become externally of an orange colour, 

 and traces of a proper enclosing membrane, the cells of which are 

 extremely indistinctly marked, are nbw visible. The membrane ap- 

 pears to have no connection with the interior of the loculus. The 

 cells composing the mass have undergone some separation. They 

 consist of a hyaline membrane which appears to be of some thickness ; 

 it is generally of a globular form, but often attenuate at one or both 

 ends. The granular molecular matter which originally filled the 

 whole cavity of the cell, now occupies a portion only, and never ap- 

 pears to lose its spherical form. When the perianth is two lines 

 long, the proper membrane of the mass has become more distinct ; its 

 cells contain a good deal of granular matter of a reddish orange 

 colour. The cells of the mass have become more separated, but have 

 otherwise undergone no change ; the semi-opaque nucleus presents 

 traces of division most frequently into four, often into three, and very 

 rarely into two portions. The division is more distinct towards the 

 circumference of each cell ; it may be observed in the same mass in 

 every stage, from the commencement of the dividing lines to their 

 meeting in the centre. The smaller masses or nucelli resulting from 

 this division are each enclosed in a proper cell, but as yet have under- 

 gone no separation. 



In the next stage the perianth had increased two-thirds of a line in 

 length ; the mass presented externally the same appearance. The 

 component cells had increased in size, and the divisions of the nucleus 

 had in many cases undergone complete separation from each other, 



