184 Algce a Colouring Matter in Salt Marshes. 



salinus, M. Dunal discovered another substance of a deep 

 orange-red colour, which appeared at the surface of the water. 

 On being submitted to a magnifying power of 200 times the dia- 

 meter, this substance exhibited a union of numerous individuals 

 of a species of the genus Hccmatococcus, one of the simplest of the 

 family of the Algaj,and which is characterized by its red semimdes 

 or globules. It is worthy of remark that it is another species of 

 the same genus, the Huematococcus Noltii., which gives the colour 

 to the peat-bogs of Schleswig. The cellules of the Hcematococ- 

 cus observed by M. Dunal, and which he names Salinus, are 

 spherical or elliptical, at first of an orange-red, and afterwards 

 of a ferruginous colour. In the laminae of crystalHzed salt, 

 M. Dunal observed long reddish threads. These were pro- 

 duced by the Hcematococcus salinus imprisoned in the crystals 

 of salt ; and these crystals being dissolved, the plant is repro- 

 duced in a state of perfect preservation. In the middle of the 

 salt-work of Bagnas, M. Dunal has sometimes seen floating a 

 red substance, which assumes the elongated form of a mass of 

 Confervae. The Hcematococcus salinus was at that place mixed 

 with another rudimentary alga, which is merely a simple hya- 

 line tube, without ramification or articulation, terminated by a 

 point, and perfectly empty. This is a species of Protonema, 

 to which M. Dunal gives the name of Salina. Although this 

 botanist mentions a Protococcus salinus and a Hcematococcus 

 salinus, yet he thinks that these two pretended species, which, 

 according to the divisions generally adopted, it is necessary to 

 range under two different genera, are one and the same plant, 

 which, when young, is a Protococcus, and when more develop- 

 ed is a Hwmatococcus. 



The salt assumes the tint of the different vegetables it en- 

 closes ; it is orange-red, or of the colour of rust, when it con- 

 tains the Haematococcus, and of a beautiful rose-violet tinge, 

 when it includes the Protococcus. A delightful violet odour 

 is exhaled by these coloured salts, and is retained for a year, 

 when they are heaped up in prismatic masses termed Camelles. 

 The colouring matter foi-med by the Hcematococcus, full of 

 globules of an orange-red tint, stains the hands strongly. M. 

 Dunal gives no details regarding the Artemia salina, as M. 

 Andouin has already announced that he is investigating that 

 hrancliiopodc. 



