96 HICKS, ON GONIDIA OF LICHENS. 



are, in their turn, capable of undergoing segmentation, and 

 thus multiply in that phase. Such changes are in accordance 

 with well-known conditions in other vegetables. 



Of course, Avhilst admitting the probability of these points, 

 we should be very careful that the connection is fairly traced 

 out, and assume nothing as intermediate stages without 

 ocular proof, or such circumstantial evidence as cannot be 

 escaped from. Thus the life- history of one, carefully traced, 

 Avill be worth a hundred new forms without any history. It 

 is to be observed, that the fact of these structures under con- 

 sideration having been included among the algse by algeolo- 

 gists is not to be considered any proof of their really being 

 so ; for, their life-history not having been followed out by 

 the observers of species, they can only be considered as pro- 

 visionally so placed ; as indeed must all organisms, vegetable 

 or animal, whose various states, both vegetative and sexual, 

 have not been carefully Avatched throughout. 



That many of the above points are now clear and have had 

 their exceeding ambiguity in some measure explained, will, 

 I think, now scarcely be denied. Doubtless a large field is 

 open in this direction, if care and patience be bestowed upon it. 



As I have before remarked, we must not look upon Gleo- 

 capsa, &c., as arising only from lichens. From facts which 

 have come under my notice during the observations now 

 brought forward, other origins also are to be given these 

 growths, that is to say, forms uudistinguishable from them ; 

 and hence it follows that the study of their life-history is the 

 only means of assigning them their true position. At present 

 all the so-called unicellular algie, and some Confervoidese, are 

 on a most unsatisfactory basis; nor can any arrangement 

 possibly take place till more extended researches are carried 

 out in the directions above indicated. I have placed in a 

 tabular form the different phases of the lichen-gonidium, 

 according to the observations included in these contri- 

 butions. 



