Olson: OBSERVATIONS ON G1GARTINA. 167 



Moore, S. Le M. Studies in Vegetable Biology. I. Observations 

 on the Continuity of Protoplasm. Journ. Linn. Soc. 21 : 595-621. pt. 

 19-21. 1886. 



EXPLANATION OF FIGURES IN PLATES XIII. AND XIV. 



All drawings were made from material preserved in alcohol. 



Fig. i. Group of fronds springing from a common holdfast. One- 

 half natural size. 



Fig. 2. Upper portion of fertile frond showing marginal and sur- 

 face proliferations with cystocarps produced upon them. One-half 

 natural size. 



Fig. 3. Young frond showing typical shape and single holdfast. 



One-half natural size. 



Fig. 4. Small leaflet with cystocarps. X4-5. 



Fig. 5. Four cystocarps on a small stalk-like proliferation. X4-5- 



Fig. 6. Surface view of holdfast showing scars. X4-5- 



Fig. 7. Cystocarps infected by a parasite. x5. 



Fig. 8. Surface view of nemathecia. x5- 



Fig. 9. Section through a scar of the holdfast : #, layer of cuticle 

 on upper surface ; b, region of the lower surface covered with cuticle ; 

 c, rough broken lower surface, x 5. 



Fig. 10. Section through the holdfast with rhizoid-like outgrowth 

 from the lower surface. A portion of the tissue is omitted in the cen- 

 ter, as it issimply a continuation of that represented on either side. 

 Toward the left the drawing stops in the stipe region. On the right 

 the transition from the stipe to the holdfast is shown : a, cuticle of 

 upper surface; 6, region showing cellular structure characteristic of 

 the holdfast; c, cellular structure marking transition from tissue of 

 holdfast to that of stipe ; d, beginning of tissue of the stipe ; e, curva- 

 ture of cells at juncture of stipe and holdfast, x 300. 



Fig. 1 1 . Longitudinal section of the lamina : #, cortex ; 3, outer 

 region of pith showing lai-ger pith cells; c, inner region of pith with 

 smaller cells, x 300. 



Fig. 12. Cross section of stipe: , cortex; , larger celled pith; 

 c, smaller celled pith, x 300. 



Fig. 13. Cross section of the lamina showing many pith cells con- 

 nected by pits and cortex cells connected by protoplasmic threads. 



Fig. 14. Surface view of thallus. x 300. 



Fig. 15. Outline of cross section of stipe showing cortex and pith 

 areas, x 4.5. 



Fig. 1 6. Pith cells of lamina stained with methyl violet and 

 mounted in glycerine. Cell wall is much swollen and one shows 

 stratification, x 300. 



