H^MATOCOCCUS. 327 



any perceptible order, commonly present concentric circles, 

 generally approximated, evident to the light. But the quater- 

 nary type, both in the distribution of the vesicles and glo- 

 bules, is generally preserved. The diameter of the globules 

 is constant at the two hundredth part of a millimetre ; that of 

 the vesicles varies from the hundredth to the twenty-fifth part 

 of a millimetre. 



" At a more advanced period of growth, some globules be- 

 come thicker, and manifestly include a granular substance, 

 the partial vesicles at the same time becoming dissolved, and 

 disappearing. Towards the circumference of the frond are 

 often noticed globose, elliptical, or irregularly lobed areolae, 

 which are seen to be gelatinous, and all filled with very mi- 

 nute granules scarcely the fiftieth part of a millimetre in size. 

 It appears, therefore, that each one of the larger vesicles, the 

 partial vesicles included by it being absorbed, the globules 

 having been converted into granules, is changed into a new 

 frond. As often as a fragment of the frond is compressed be- 

 tween plates of glass, the oblong gelatinous bodies enclosing 

 very small granules, which we regard as new and incipient 

 fronds, and which are always present in great abundance, are 

 lacerated, their contents poured forth, and they then cover 

 the other parts with the thin mucus with which they are 

 themselves enveloped; and from this C. Kiitzing appears 

 to have asserted that the vesicles were enfolded, the green 

 stratum enclosing very minute granules. It is yet remark- 

 able that the multiplied and concentric vesicles escaped the 

 celebrated Kiitzing and the acute Lyngbye." Meneghini. 



7. HJEMATOCOCCUS GKANOSUS Harv. 

 Plate LXXXI. Fig. 6. 



Char. Crust widely spreading, granulated, pale green. Cells 

 polymorphous, formed of two or three vesicles, and each 

 containing one, two, or four green, large, elliptical granules 

 with distinct hyaline borders. 



Y 4 



