MACROGENS. 



451 



and importance as this, many will, and with reason, dislike so important 

 an assumption on such inconclusive evidence, But with our present 

 means, it appears to me probable that no evidence to demonstration 

 can be looked for, and for this reason, that the contents of these 

 peculiar cells are so subtile as to escape definition even while in their 

 cells, (or under the most favourable circumstance for a concentra- 

 tion of attention.) How much more so will this be the case, when 

 we attempt to examine the steps of the application of the fecundatory 

 matter, applied over a surface without any prominent points, and 

 probably opaque. 



When direct evidence is not to be had, we are justified in using 

 presumptive evidence. As in human law, so in the laws of nature, 

 presumptive evidence to a practised eye carries with it conviction. 

 We have no direct evidence how the embryo is formed, yet no one 

 doubts but that it is brought about by the agency of the boyau, 

 which is a cell containing grumous molecular matter. However 

 different a boyau may seem to many, yet when viewed in conjunction 

 with Cycadeae, the graduation to the present case becomes natural, 

 and even the resemblance may be perfect, because in Cycas the grains 

 of pollen get into the nucleus bodily, although they would still seem 

 to throw out short tails. 



Wonderful is the simplicity of nature ! The male organ in its 

 essence, consists of a single cell containing molecular matter. 



The female in its essence consists of a single cell, likewise con- 

 taining similar matter. The influence of the male is exerted, and so 

 another cell is formed in the female cell, and this either becomes the 

 embryo, or gives origin to another cell, and so on, until the terminal 

 one becomes the embryo, 



I believe from examination of the most developed scaly ramenta, 

 that these have at an earlier period been fecundating organs, the same 

 peculiarities are to be detected towards their ends, where in fact they 

 retain their original structure, the dilated base being a subsequent 

 development. 



In reference to this, the examination of young ferns on their arrival 

 at the age of puberty is indispensable. A curious question arises, what 

 is the frond of a fern ? Is it a mass of foliaceous growth containing 

 certain lines of reproductive matter, or is it a distinct development 

 from the axis, in which the reproductive organs are situated ? Is it, 

 or is it not, subservient to reproduction ? Here again extensive exami- 

 nation is necessary. 



