Olson: OliSIiKVATIOXS ON GIGARTINA. 107 



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

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

 ig-2i. 1SS6. 



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. x 4-5- 



Fig. V Four cvstocarps 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 : a, layer of cuticle 

 on upper surface; (5, 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 : (7, cuticle of 

 upper surface ; <5, region showing cellular structure characteristic of 

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

 holdfast to that of stipe ; rf', beginning of tissue of the stipe : e, curva- 

 ture of cells at junctui-e of stipe and holdfast, x 300. 



Fig. II. Longitudinal section of the lamina: a., cortex; <5, outer 

 region of pith showing larger pith cells ; c, inner region of pith with 

 smaller cells, x 300. 



Fig. 12. Cross section of stipe: a^ cortex; b^ 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. 

 X300. 



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



Fig. i^. Outline of cross section of stipe showing cortex and pith 

 areas, x 4.5. 



Fig. 16. Pith cells of lamina stained with methyl violet and 

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

 sti-atification. X300. 



