192 Objects for the Microscope. 



Ptilota plumosa, being found in long crimson feathery 

 sprays on the coast after storms, or dredged in deep water. 

 It is a great favourite with collectors of sea-weed for orna- 

 mental purposes, and is equally valuable for the microscope, 

 yielding two kinds of fructification ; the Ceramidium, con- 

 taining pear-shaped spores, and the Stichidia, containing 

 tetraspores, ranged in transverse bands. 



A delicate section of the lower part of the stem will show 

 the internal structure, which is of numerous parallel tubes 

 surrounding a central cavity, and edged with a circle of the 

 short stout hairs which clothe the stem. 



Sections of the fruit and of the stem are often indispen- 

 sable for determining the species, and give innumerable 

 varieties of beautiful objects. 



DASYA ARBUSCULA. 



A delicate plant not uncommon at the verge of low-water- 

 mark in many parts of Scotland and in the Channel Islands ; 

 remarkable for its beautiful and abundant stichidia, clustered 

 amidst the fine ramuli, which cover the- frond densely, and 

 are forked at the tip, jointed, and of a clear crimson-lake 

 colour, sometimes more or less brown, and always discharg- 

 ing its fine colour if left in fresh water. 



DASYA OCCELLATA 



is of a purple colour, and the dense tufts of ramuli at the 

 tips of the branches give it a dotted appearance, like an 

 eyelet on each delicate feathery stem. The stichidia are 

 very long slender pods, full of tetraspores. 



DASYA VENUSTA. 



A most beautiful and rare little plant, found in the 

 Channel Islands in summer and autumn. The shape of 

 the stichidia, which have long acute points, and the re- 

 peatedly forked ramuli, distinguish it from Dasi/a arbuscula, 

 which it otherwise much resembles. 



These marine Algae are prepared in Paris, by Bourgogne, 

 and sold by Baker, of High Holborn. A collection of even 



