THE society's NOTE-BOOKS, o7 



confervse and fungi — ^that we can more plainly trace the primitive 

 forms of the results of this law. Taking the fungi, and com- 

 mencing with the unicellular yeast-plant, we follow to Oidiiun and 

 PenicilluDJ^ where the cells are joined at their ends, then to Peri- 

 cofiia and ArtJirobotryum^ where they are compacted into a 

 common stem, and so on to the Agarics, which are considered the 

 highest form of fungi. 



There is a very interesting article in the Popular Science 

 Revietv, April, 1880, showing the application of this law to 

 the Animal Kingdom, especially as regards the Polypes. 



This law, which accounts for the cellular structure of plants, 

 lends additional interest to the study of Botany. W. C. Tait. 



Trichooolea tomentella.— Liverworts are either stemless, with 

 creeping fronds, or they have leafy stems. The Trichocolea tomen- 

 tella (sub-order, Jungermanniece) belongs to the latter. It is found 

 in moist places in the west and north of England, Scotland, and 

 Ireland, and is remarkable for the character of its leaves, which 

 are much divided, giving the plant the appearance of an Alga. 

 The roots are simple elongated cells, tubular, white, transparent, 

 scattered in small tufts, and springing from the lower surface of 

 the leafy stems. H. M. Klaassen. 



EXPLANATION OF PLATES IIL, IV., V., VI. 



Plate III. 



Upper Portion. 



Fig. 1 .■ —Longitudinal section of Alder, x 100 diam. , showing 0., 

 outer; m., middle; i., inner, layer of the bark ; e, , single 

 layer of cells, the " epiderm ; " c, corky layers ; f.L, fibrous 

 layer, with its raphides and bone-cells ; m.r., medullary rays ; 

 w.f., woody fibre ; ^J.d, pitted ducts. 



,, 2. — Portion of two pitted ducts more enlarged to show the mode 

 of union, x 200. 



,, 3. — End of a pitted duct, showing scalariform-like structure. 



„ 4— "Bone-cells." 



,, 5. — " Crystal prisms " in the section under observation. 



,, 6. — " Spyeraphides," in a section of my own (T. West) preparing. 



Lower Portion. 



,, 7. — Portion of Skin of Dog-Fish magnified 2.5 diam., showing 

 various forms of scales, two in process of development, and 

 pigment in part. 



