HoLLOWAY. — Studies in the New Zealand Species of Lycopodium. 273 



upper region becomes lobed (fig. 34), and these lobes soon show them- 

 selves to be two main branches (figs. 35, 37, 38), each of which also 

 develops secondary lobes. A large n*umber of young prothalli of this 

 age were collected, and they were all seen to show more or less clearly 

 the Y form. In older specimens there is an extended and slightly concave 

 flattened upper surface, the concavity being more or less obscured by 

 irregular lobing and folding (figs. 41 and 44). The original two main 

 branches can always be distinguished in an underneath view of the 

 prothallus (figs. 40 and 42). The view from above also in some cases 

 shows this, and shows as well, in spite of the complexity of the folding 

 of the upper surfaces, that each main branch has divided into two 

 branches, so that the upper surface is somewhat quadrangular in form 

 (fig. 41). The first branching of the prothallus always takes place very 

 early, so that in the older prothalli the jjeg-like projection is never 

 as long and tajDering in this species as it is in L. voluhile. In the 

 young prothalli the rhizoids arise especially from the upper ends of the 

 two branches. The lobes are always clearer in appearance than the 

 rest of the prothallus, which is in colour dingy white. None of the 

 prothalli showed any trace of chlorophyll, being always more or less 

 deeply buried. 



L. scariosum. 



Miss Edgerley (8, pp. 100-2) states that the prothallus of this 

 species resembles that of L. clavatum. I would unhesitatingly, how- 

 ever, say that it approaches more closely to the type of L. coni- 

 ■planatum as described by Bruclimann (6). The material examined 

 by Miss Edgerley had been collected by the present writer, and 

 had been killed and fixed in 80 per cent, alcohol, and there is no 

 doubt that it had shrunk considerably by the time that Miss Edgerley 

 studied it. Hence she describes the upper surface of the prothallus as 

 " concave . . . with a ridge running round the margin." In 

 figs. 45-53 in the present paper are depicted fresh prothalli of this 

 species, and it will be see that they correspond very closely in general 

 form to those of L. complanatum figured by Bruchmann on plate V and 

 described by him on pp. 57—59 of his work. Tliere is, however, one main 

 difference — namely, that old prothalli of the New Zealand species grow 

 to a great size and become very irregular in form, so that a pseudo- 

 branching is sometimes to be observed in them. The prothalli show a 

 conical region below, in some cases blunt and rounded, in others more 

 tapering, Avhile above they are more massive. In the prothallus of this 

 species there is no definite horizontal extension of the upper portion or 

 lobing, such as there is in that of L. voluhile. The upper region is 

 surmounted by a bulky convex mass of tissue. Avhich is semitranslucent 

 in appearance, and is separated from the main body of the prothallus 

 by a well-marked neck. In partially depleted prothalli, and in pro- 

 thalli which have shrunk in alcohol, this upper tissue becomes slightly 

 concave, but in fresh material it is seen to be invariably rounded and 

 massive, and is not surrounded by a rim, but bulges out over the main 

 body of the prothallus. In such an old specimen as figured in fig. 53 

 this upper tissue constitutes the major bulk of the prothallus. A 

 longitudinal section of a medium-sized protliallus, such as anv of those 

 shown in figs. 45-48, corresponds almost exactly with that figured 

 by Bruchmann (6, pi. V, fig. 25). My observations are, however, in 

 agreement with Miss Edgerley's statement that the various lavers of 



