520 THE NATURAL HISTORY OF 



water. They then increase in size, become organised 

 internally, and surrounded with a membrane derived 

 from a thickening of the peripheric layer of the spores. 

 They are thus transformed into H. pluv. atomariu-s, 

 which, in the course of further development, becomes of 

 a rose-red colour and gelatinous, surrounded with a 

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

 mucosns ; 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 Hcematococcus. 



Another motile form is of a smaller size, distinguished by 

 its active motion, and characterised as H.pluv. porpl/i/ro- 

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

 0-0004 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 



