Objects for the Microscope. 187 



them inhabitants of the rock-pool, some of the wide wild 

 ocean, growing on the stems of Laminaria, and therefore 

 often found upon the beach after a storm, or obtained by 

 dredging on all the British coasts. It also loves to grow 

 upon Melobesia on the steep sides of rock-pools. 



Of all these the P. urceolata and P. elongella are the 

 best for microscopic observation. The former has a beau- 

 tiful fructification ; an urn-shaped capsule called a cerami- 

 dium, furnished with a pore or opening like the mouth of a 

 vase, and containing a tuft of pear-shaped spores. 



A second form of fruit is met with on the same plant ' 

 the tip of a branch expands, and a row of tetraspores is 

 imbedded in it ; also on Polysiphonia fastigiata such an 

 abundance of antheridia is found as to give a yellow colour 

 to the plant, quite visible to the naked eye, and deserving 

 particular microscopic observation. 



SPHEROCOCCCS. 



A common plant, often cast ashore after a gale, and 

 found all along the coast of Cornwall and Devonshire, Isle 

 of Wight, and the Channel Islands. 



It is difficult to obtain perfect specimens of the beautiful 

 fructification, they are so often destroyed by the violence of 

 the waves ; but a careful dissection of it freshly gathered 

 would be both delightful and instructive. 



We find minute spherical capsules supported on slender 

 stalks and mucronate, that is having a little spine obliquely 

 projecting from their apex ; upon opening this, by making 

 a section through it, we see a cluster of crimson seeds, also 

 stalked. The structure of the branches should be noticed ; 

 they are obscurely but perfectly veined, a faint narrow 

 mid-rib and lateral parallel veins may be distinctly seen. 



GRIFFITHSIA, 



so named in honour of Mrs. Griffiths of Torquay, found on 

 the coast of Devonshire, and other parts of the southern 

 coast of England. The frond is rose-red, filamentous, and 

 jointed. The fructification is of two kinds : 



1. Tetraspores affixed to whorled involucral ramuli or 

 small branches. 



