MISCELLANEA B31Y0L0GICA 139 



The branches in P. Kuhliana, however, are to my eye quite 

 as much flattened as in the Samoan plant; moreover, the Bryol. 

 javanica describes P. Kuhliana as "folia compressa," and figures the 

 branches as complanate, and I am clear that this is not a separating 

 character, and that the two are identical. 



This conclusion is confirmed by C. Mueller's remarks in Musci 

 Polynesiaci, on Hypnum elegantissimum (Mitt.) C. M. There are 

 two rather distinct forms of the Samoan plant, one with densely 

 pinnate, stout, short branches, the other with distant, slender branches, 

 often attenuated and filiform. C. Mueller refers to these two forms, 



comparing the former with P. KuMiana (" gleich ganz dem 



P. Kuhliana"), while the other he compares with Porotrichum 

 J a mi in Bry. jav., which Fleischer has reduced to a synonym of 

 P. Kuhliana ! 



P. Kuhliana must therefore be recognized as extending into the 

 South Seas, including Samoa and Fiji, and New Caledonia. It is 

 very near to P. mucronata (Bry. jav.) Fleisch. ; the latter, however, 

 has the leaves more constantly and more strongly mucronate, and a 

 much weaker nerve, apart from minor differences. 



Gymnostomum okanicum Behm. 

 In my " Miscellanea Bryologica " Part vi. ( Journ. Bot. Ivii. 75 

 (1919), 1 referred to this moss, and pointed out that it is a true 

 Weisia. Prof. Holzinger shows {Bryologist, xxiii. 8) that the 

 correct citation is not, as C, Mueller gives it, Weisia oranica llehm., 

 but W. oranica (Behm.) C. M., since Behmann placed it under 

 Gymnostomum, not under Weisia. 



THE LICHEN LIFE-CYCLE. 

 Bi A. H. Chuech, 



Even more interesting than the significance of the somatic 

 organization of the Lichen-type of plant is the parallel history of the 

 origin of the mechanism of the reproductive organization, as also the 

 progressive modification of the latter, in following the same sequence 

 of transmigrant stages from the sea to the changing conditions of 

 reef-pool formations, with ultimate translation to subaerial existence 

 and conditions of extreme xerophy tic exposure 1 . The complexities 

 of reproductive organization admittedly represent the mechanism 

 of racial continuity ; and it is generally accepted that this class of 

 phenomena affords a satisfactory guide to the relations and affinities 

 of an organism to a much greater extent than does somatic organiza- 

 tion which may be confused by more superficial adaptations to the 

 immediate needs of the individual life. That is to say, the repro- 

 ductive mechanism is more likely to retain vestiges of older construc- 

 tions, and so to afford glimpses of previous somatic phases of the 

 race. That such processes may be in some respects more ' conserva- 

 tive,' is, in fact, the general teaching of all morphology, of both 



1 ' The Lichen as Transmigrant,' Journal of Botany, 1921, p. 7. 



l2 



