CHILEAN SPECIES OF METZGERIA. 



293 



At the time of separation the gemmae are flat and unistratose struc- 

 tures, orbicular to oblong in outline, broadening out abruptly from a 

 two-celled and often indistinct stalk, and showing a broad and rounded 

 apex with a single apical cell. They are mostly 0.25-0.3 mm. long and 

 0.18-0.25 mm. wide, being composed of six to eight indefinite rows of 

 cells. On each side six to eight hairs are usually present, and these 

 are commonly (but not invariably) arranged in pairs. The hairs 

 extend almost at right angles to the surface of the gemma and, when 

 paired, spread in opposite directions. The majority are strongly 



Fig. 5. Metzgeria patagonica Steph. 



A. Female branch, X 50. B. Germinating gemma, 

 figures were both drawn from the type material. 



X 100. The 



curved and might often be described as hamate. Only the earliest 

 stages of germination have been observed and in these the young 

 plants have simply repeated the features of the gemmae, except that 

 they have sometimes been a little narrower (Fig. 5, B). In other 

 words they have remained flat and unistratose thalli, showing no signs 

 of dorsiventrality and tending to produce a succession of paired and 

 divergent marginal hairs. 



Marginal gemmae with hooked hairs have been described in M. 



