90 INTRODUCTION. 



excrescences similar to moss. It seems that this 

 disease also appears in young carp which live in 

 corrupted, or snow-water; which latter also pro- 

 duces particular germs under the scales, which 

 fishermen call the Small-pox." (L. c. x. 453). In 

 January last, Mr. Goodsir communicated to the 

 Royal Botanical Society of Edinburgh a description, 

 with a drawing, of a vegetable found upon the gills 

 and fins of a Goldfish, with a minute account of 

 the parasite, explaining its form, structure, and 

 mode of fructification. This Memoir we have not 

 seen ; probably it is not yet published. Dr. Bennet 

 gave an account of these fungi to the Royal Society 

 of Edinburgh in the month of February last. " To 

 the eye/' he remarked, " they presented the appear- 

 ance of white cottony, or flocculent matter, attached 

 to the animal. Under the microscope two distinct 

 structures were perceived, one cellular, the other 

 non-cellular. The former consisted of long tubes, 

 divided into elongated cells by distinct partitions. 

 At the proximal end of several of these tubes there 

 was an exceedingly minute transparent vesicle or 

 nucleus. Some of the cells were filled with granu- 

 lar matter, others were empty, the granules having 

 escaped through the rupture of the cellular walls. 

 Besides these there were long filaments, very slen- 

 der, which sprung apparently from the sides of the 

 cellular tubes. These were uniform in size through- 

 out their whole length, and were formed of an ex- 

 ternal diaphanous sheath, and an internal more 

 solid matter. The vegetable sprang from a finely 



