INTRODUCTION TO CEYPTOGAMIC BOTANY. 53 



cotyledonous as in plants which represent the typical struc- 

 ture of the stem more completely, and multitudes of similar 

 instances might be alleged.* If Nym'phoBa, again, be taken, 

 the embryo, when properly understood, is as distinctly dicotyle- 

 donous as in any other plant ; and if further proof were wanted, 

 the germination of the common pseony should be compared with 

 it. Each group of organisms has a circle of its own in which they 

 are combined by close affinities, and these circles are not the less 

 definite, because there may be an osculating point with some 

 other circle. The two great groups of fungi, for instance, 

 characterised by naked and inclosed spores, are perfectly 

 definite. Even in those cases where the inclosed spores 

 are reduced to one closely invested by the outer coat, so 

 as to look naked, the morphology is as definite as ever, and 

 the genus Haplosporium in which this character is most pro- 

 minent is, in fact, one of the noblest, and by no means a form 

 of transition. Except where the naked spore is a secondary form 

 of fruit, there is never the slightest doubt as to the true affinity. 

 It may be true that in Hymenogaster a sac is occasionally 

 developed round the spores, but the spores are then as perfect 

 and as definitely placed as in other species where there is no 

 such sac, the presence of which is a mere analogy and not an 

 homology. What, in point of fact, is necessary to the suc- 

 cessful study of this or any other branch of science, is to 

 avoid mere speculation ; to endeavour to grasp, if possible, the 

 exact meaning and import of every modification which occurs, 

 by close comparison and observation of nature. A person 

 who should set out on an investigation of the phenomena 

 of impregnation in Phaenogams, with a decided prejudice 

 in favour either of the Schleidenian notion of the penetration 

 of the end of the pollen tube into the embryo-sac, or of 

 its simple contact with the sac apart from any introversion, 

 would be sure to see facts with eyes already more than 

 half -blinded. If any proof of this were wanting, it would be 

 found in the curcumstance that the same identical specimens 

 and preparations have very lately led two different German 

 botanists to precisely different conclusions. The real object 

 * The truth is, the majority are undoubted members of Liliacex. 



