36 Morphologie. 



region are embedded in the soil ; Chlorophyll is absent, from 

 them, while rhizoids are numerous, especially on the tubercle. 

 In the Upper swollen portion of the cylindrical region and in 

 the terminal region, which is unlobed, Chlorophyll is present. 

 The meristem is situated between the cylindrical and terminal 

 regions and its position is often indicated by a constriction. 

 The prothallus consists of parenchyma the axial cells being 

 somewhat elongated; the cells contain abundant starch. A 

 symbiotic fungus is contained in the cells of the lower half; 

 its hyphae often form a close feit around the tubercle. The 

 prothallus is monoecious ; the sexual organs are produced in 

 basipetal succession above the meristem. The archegonia have 

 a Short, slightly projecting neck, formed of two tiers of cells. 

 The antheridia are sunk in the tissue of the prothallus; their 

 wall is one layer of cells thick. Paraphyses are wanting. The 

 development of the embryo resembles that of Lycopocliiim 

 cernuum, the apex of the stem and the first leaf being derived 

 from the part next the archegonial neck. The embryo is 

 attached to the prothallus by a foot; the first leaf grows verti- 

 cally; the apex of the stem becomes depressed and enclosed 

 in the first protocorm, which is forced into the soil by the 

 elongation of its pedicel. No root has been noticed during 

 the first year of growth, but rhizoids may be developed on the 

 protocorm. The development of the plant in successive years 

 proceeds in the manner described by other authors for older 

 specimens; even in the third year only a Single protophyll 

 may be produced. The author suggests that the prothallus of 

 Phylloglossum may be regarded as the simplest known type 

 among Isosporous Lycopodiaceae. The latter portion of this 

 paper contains observations on the branching of the axis in the 

 plant of Phylloglossum and on the common production of 

 more than one protocorm from a Single plant. The author 

 regards the protophylls as of independent origin from the sporo- 

 phylls and criticises the view that Phylloglossum is to be 

 regarded as a reduced rather than as a primitive form. 



W. H. Lang. 



PlERCE, Geo. J., Studies on the Coast Redwood, Se- 

 quoia Sempervirens Endl, (Proctor California Academy 

 of Science. Ser. III. II. 1901. p. 83.) 



The author describes the formation of white suckers from 

 the stumps of old redwood trees. He finds that the white leaves 

 and stems differ materially from the green suckers of the same 

 locality, particularly in the thinner cellwalls, and in the com- 

 plete absence of the palisade parenchyma. He ascribes the total- 

 absence of Chlorophyll to the absence of sufficient warmth at the 

 time the buds start to form the suckers, and discusses this at 

 some length. The white forming sucker derives all of its 

 nutrition from the Underground parts of the tree, i. e. it is a 

 distinct parasite, which has lost the faculty for forming chloro- 



