178 Dr. Schleiden 07i the Development of the 



The incorrectness of Agardh's view is also made evident by 

 aconsiderationofthose flowers, in which the internode between 

 petals and stamens is perfectly developed, as in some Cappa- 

 ridece. 



The regularly formed leaf consists of a central rib, on each 

 side of which there is a twofold cellular tissue, between which 

 the nerves take their course. In this manner is the anther 

 naturally formed, whose superior and inferior cellular tissue* 

 is converted into pollen on both sides of the principal nerve ; 

 thus is formed the anther with four cells, which we find to be 

 the general law. 



I have found the anther before its bursting quadrilocular in 

 more than one hundred families ; amongst these I may name 

 Graminece, CyperacecE, Liliacece, Labiatcc^ Borraginea^ Scro- 

 phularinece^ Synantherecc, Umbelliferce, RanunculacecB with 

 its allies, Rosacece (Juss.), and the Leguminosce^ which alone 

 constitute almost one-half of the entire vegetation of the 

 globe. It has been often asserted that the anther could 

 not originally be quadrilocular, since it springs open with 

 two fissures only ; that is as much as to consider two chambers 

 as one, because they have not folding doors, but simple doors 

 placed close together. Properly speaking every anther really 

 bursts open with four fissures; they appear however only as 

 two because each pair lies at the sides of the common septum. 

 The difference between quadrilocular and bilocular anthers of 

 descriptive botany, (here however the Anthercc dimidiatce 

 and some few others must be excepted,) consists in this alone : 

 whether the valves detach themselves from the septum earlier 

 or later, in the close observation of which we may distinguish 

 every state of transition. 



Sometimes, though rarely, the original middle layer is not 

 developed, and in this case of course the division into two 

 lateral cells is not found. Still more rarely is the one lateral 

 half of the leaf only developed into an anther, the other retain- 

 ing its leafy character ; this condition is the type of the Maran- 

 iacece, and occurs frequently as monstrosity in the conversion 

 of the floral leaves into stamens, or of stamens into petals. 

 In both cases, however, the course of the epidermis proves 



* The normal leaf, as is well known, exhibits upon its upper surface 

 cellular tissue, different in structure from that on the under; to this we 

 find that the pollen of the anterior and posterior cells of those compart- 

 ments corresponds. It may perhaps be possible, and certainly not unin- 

 teresting, to ascertain by experiment, whether or not the pollen of one 

 of these compartments only possess the external characters of pollen, 

 and likewise different functions in the process of imj)regnation, or whether 

 in Dioecious plants one kind would produce male, the other female em* 

 bryos. 



