520 THE NATURAL HISTORY OF 



water. They then increase in size, become organised 

 internally, and surronnded with a membrane derived 

 from a thickening of the peripheric layer of the spores. 

 They are thus transformed into H. pliw. atomarius, 

 which, in the com-se of further development, becomes of 

 a rose-red colour and gelatinous, surrounded with a 

 mucous envelope, and constitutes the form of H. pluv. 

 mucosus ; which is finally transformed again into the 

 normal form. The dispersion, therefore, of the red 

 spores is not a proceeding without object, or a morbid 

 process, but subservient, in an incredible degree, to the 

 multiplication of the plant. 



In a favorable season, and when the vegetative powers 

 are in full activity, the spores, after their expulsion, 

 remain adherent to each other, connected by a mucous 

 material, afterwards becoming free, and successively trans- 

 formed into the motile form of Hamatococcus. 



Another motile form is of a smaller size, distinguished by 

 its active motion, and characterised as H. pluv . porphyro- 

 ccphalus. It has a flask-like or obovate form, 0'0002 — 

 00004 Paris inch in length, with a red capitate projection 

 at the anterior extremity, and ventricose posteriorly. 



In general, from the motile condition all these forms 

 pass immediately into the still form. But the alterna- 

 tion between the still and motile forms depends alto- 

 gether upon external conditions, and is by no means 

 capricious. Whether the still form, upon its division, 

 develop motile individuals, depends upon the light and 

 temperature. 



Multiplication by division {status viviparus) occurs 

 both in the still and in the motile forms. The contents 

 of the mother-cell, surrounded by a mucous envelope, 

 divide into four (frequently more) portions, each of 

 which includes a central particle of red matter, and sur- 

 rounds itself with a gelatinous membrane. 



The division frequently commences in the motile con- 

 dition, and continues in the still. The younger indi- 

 viduals, with red mucous globules, spores, buds, and 



