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riT"^ BEGINNINGS OF LIFE. 



245 



deli<Tht I found it studded with thousands of embryo 

 P^r^wzm^, whilst others were free and active 



the 



a most significant fact 



infusion. It was, therefore, 

 that they should have been met with on the very first 

 occasion that a cold maceration had been employed ^ • 

 whilst not a single Paramecium had ever been seen before 

 any of the many hay infusions kept in the same 



m 

 place 



t> 



them 



with water whose temperature was not more than 

 i25°-i30°F, and which therefore was not high enough 

 to have killed any embryos that may have chanced to 

 pre-exist in the infusion previous to its filtration. 



The maceration was at the time covered by a thick 

 pellicle, which had become brown on its upper surface. 

 Its under layers, however, were still soft and pulpy. 

 When a small portion of it was transferred to a micro- 

 scope slip, and gently compressed by the covering glass 

 so as to flatten it out into a thinner layer, the granular 

 membrane was observed to be pretty thickly studded 



\ 



1 Owing to the coldness of the weather (the daily temperature of the 

 room being scarcely above 6o°F) they did not make their appearance in 

 the pelUcle till more than fourteen days ; although with a daily tempera- 

 ture of 75° F they are said by M. Pouchet to begin to make their appear- 

 ance on the third or fourth day. I had examined the pellicle of my 

 maceration from time to time during the first week, but did not look at 

 it subsequently for several days— not, in fact, until the day on which I 

 received M. Pouchet's letter. During the first week the pellicle had 

 become very thick and pulpy, but the weather being rather colder at 

 this time, it was principally giving birth to various kinds of Fungus- 

 germs. / 



^ Beneath a bell-jar in my study. 



