180 JOURNAL OF THE [July> 



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name of the Red Sea, though a much more reasonable one is 

 found in the theory just mentioned with reference to the 

 prevalence of red sea-weed. As to the appearance of blood 

 .in bodies of fresh water, we need to seek no further for a basis 

 of fact than the well-known and well-understood circumstances 

 connected with the characters and life-histories of some of the 

 protophytes ; for example, the common Pfotococcus pluvialis, 

 which, though usually green, is sometimes red, and which multi- 

 plies at times with most amazing rapidity. With regard to 

 this remarkable organism I cannot do better than to quote Dr. 

 Carpenter again, who says of it (p. 281) : " Rapid evaporation of 

 the water in which the ' motile ' forms may be contained, kills 

 them at once ; but a more gradual loss, such as takes place in 

 deep glasses, causes them merely to pass into the ' still ' form ; 

 and in this condition — especially when they have assumed a 

 re4 hue — they may be completely dried up, and may remain 

 in a state of dormant vitality for many years. It is in this 

 state that they are wafted about in atmospheric currents, and 

 that, being brought down by rain into pools, cisterns, etc., 

 they may present themselves where none had been previously 

 known to exist ; and there, under favorable circumstances, they 

 may undergo a very rapid multiplication, and may maintain 

 themselves until the water is dried up, or some other change 

 occurs which is incompatible with the continuance of their 

 vital activity. They then very commonly become red through- 

 out, the red coloring substance extending itself from the centre 

 towards the circumference, and assuming an appearance like 

 that of oil-drops ; and these red cells, acquiring thick cell- 

 walls and a mucous envelope, float in flocculent aggregations 

 on the surface of the water." 



II. Showers of Blood are in great part accounted for in 

 what has just been said ; but there is one class of these san- 

 guinary prodigies which is referable to a very curious phenom- 

 enon that takes place in the insect-world. You will find an 

 account of several such wonderful occurrences in " Science 

 Gossip " for 187 1, page 45. One of the cases there mentioned 

 happened in July, 1608, when " a supposed shower of blood 

 fell for several miles around the suburbs of Aix-la-Chapelle. 

 The cause of this was discovered by M. de Peiresc to de- 

 pend upon the exudation of large drops of a blood-colored 



