1916] ROE—SPLACHNIDIUM 407 
9. Linnaeus, C. von, Mantissae Plantarum. Holmiae 1767. 
Io. Mrrcuett, M. O., and Wutrtine, F. G., On Siecinidion seal Grev., 
the type of a new oni of algae. Phyc. Mack, r:1-10. pls. 1-3. 1892. 
11. Murray, G., Introduction to the study of seaweeds. Lon on. I 
12. , On ihe wi Rags of Adenocystis, Alaria, and Sacchotbina, 
Phyc. Mem. 2:50-63. pl. 16. 
13. OLTMANNS, F., Morphologie saad Biologie der Algen. Jena. 1905. 
14. Roz, M. L., The development of the conceptacle in Fucus. Bor. Gaz. 
61:231-246. pls. 14-17. 1916. 
15. SAUVAGEAU, C., Sur la sexualité hétérogamique d’une — (Saccho- 
rhiza bulbosa). Compt. Rend. Acad. Sci. 161:796-799. 
, Sur les débuts du développement d’une at (occhorbite 
bulbosa). Compt. Rend. Acad. Sci. 161:740. 1915. 
17. Smiru, A. L., and Wurrtine, F. G., Notes on the sori of Macrocystis and 
Postelsia. Pla Mem. 1:84-86. pl. 20. 1895 
18. Sunr, J. N. von, Beitrige zur Algenkunde. F lora 24:257-298. 1840. 
EXPLANATION OF PLATES XIV-XVIII 
All the drawings were made with the aid of the Abbe camera and reduced 
one-half in reproduction. For figs. 1-21, original magnification was 1580; 
for fig. 22, 790; and for figs. 23, 24, 1050. : 
Fic. 1.—Modified superficial cell, tee heavy coat of mucilage which 
distinguishes initial row from other border ce 
IG. 2.—Two-celled stage of initial row. 
Fic. 3.—Three-celled stage of same. 
Fic. 4.—Two stages in development of initial rows; a two-celled stage 
at right and an older stage at left in which some of the cross-walls have bee: 
resorbed. 
Fic. 5.—A linear row of the thallus, showing mucilage coat characteristic 
of an initial row 
Fic. 6. het initial row in which cross-walls have been almost completely 
gen traces of old walls still distinguishable. 
- 7-—A cut showing how initial row is usually terminated by sister 
a: one of — usually fails to mature but sometimes initiates a young 
hair, as in fig. 2 
Fic, 8 att initial row together with a young hair. 
— F IG, tag —Basal portion of a branch of an apical hair which has become an 
initi 
Fic. to. Rieurnais branch and basal portion of apical hairs which have 
become “initials,” 
Fic. 11.—Basal portion of an old apical hair in which cross-walls have 
been resorbed; the upper portion (unshaded) will be shed later. 
IG. 12,—An ordinary vegetative hair characteristic of apical region. 
