176 Dr. Schleiden ofi the Development of the 



which the cotyledons are very small, that the leaves are also 

 rudimentary, and in Cuscuta the absence of the cotyledons in 

 the embryo even points to the subsequent habit of the plant. 

 The close agreement between the cotyledon of grasses and 

 the leaves has already been alluded to in the preceding note. 



The investigation of the laws of position of the leaves forms 

 a very interesting section of this inquiry ; the manner in 

 which the varying relations of foliage become developed out of 

 the originally opposed and perfectly cotemporaneous cotyle- 

 dons, until nature often appears to return at the extremity 

 of a plant to the original type of two opposite leaves. The 

 consideration of this subject would however lead me too far 

 beyond the limits of these brief remarks. 



It will be unnecessary that I should make any remark as 

 to the calyx and corolla being foliaceous organs, since that 

 is universally received. I will merely remark that in all mo- 

 nopetalous calices and corollas, those parts which at a later 

 period are joined together, forming the single leaf, are in the 

 earlier stages without exception so independent as to render all 

 discussion as to the number of the individual parts superfluous, 

 since it is a matter of investigation to be established by actual 

 evidence. Every flower then has in its earliest development a 

 regular construction, and the supposed abortions which some- 

 times appear in the arrangement of the leaves, and which have 

 often been so completely misunderstood, especially whilst the 

 diversity of the laws as to number was disregarded, are therefore 

 entirely unfounded, wherever they cannot be actually proved. 



The Euphorhicje have with injustice been denied the bene- 

 fit of their original structure. Their involucrum is not form- 

 ed out of five leaves, but out of two quintuple verticils, of 

 which the outer one develops the glands ; these even exhibit 

 earlier than the five inner leaves a middle nerve with evident 

 spiral vessels, which cannot therefore be considered to be vasa 

 recurrentia from the other. There can nowhere be found a 

 better example of the original regularity of structure of the 

 flower than in the grasses, in which the flower becomes at a 

 later period so contorted by unequal development, adhesions, 

 and suppressions of individual parts that every possible ex- 

 planation has been offered excepting that which nature herself 

 offers. For instance in Secale cereale, the spicula consists of 

 a lateral rachis, on which about five alternating flowers are 

 formed. The superior three of these, together with that por- 

 tion of the axis which appertains to them, remain in a rudi- 

 mentary state, whilst on the other hand the two inferior are at 

 first perfectly regular in their development. In the axilla of 

 every bractea {gluma auct.) we find a flower consisting of a 



