Rupert Jones, on Bivalved Entomostraca. 39 



lime is mixed with dilute hydrochloric acid, and the butyric 

 acid distilled off. 



The nitrogenous matter of the Mycoderma vini cells pro- 

 bably acted in the experiment above described just as the 

 casein of the cheese operates in the process of Pelouze and 

 Gelis ; but whether the butyric acid disappeared by simple 

 evaporation, or by chemical action, is not evident. Professor 

 Miller states, in his ' Elements of Chemistry,' that butyric 

 acid volatilizes at ordinary temperatures, but a chemical 

 change probably occurred. 



Our great authority upon Fungi, the Rev. M. J. Berkeley, 

 and Mr. Hoffman, of Margate, raised penicilium from insu- 

 lated cells of yeast ;* and as penicilium has been raised 

 in the experiments just detailed from the Mijcoderma vini of 

 M. Pasteur, it would appear that the cells of that organism 

 belong to one of the many forms which the yeast plant is 

 able to assume. 



Bivalved Entomostraca, Recent and Fossil. 

 By Prof. T. Rupert Jones, F.G.S. 



(Read January 8th, 1868.) 



Ever since naturalists have clearly seen that the many 

 different layers or beds of stone, clay, and sand, of which 

 the earth's surface is composed, were formed by the deposits 

 of mud, silt, and shingle of old oceans, not by any mysterious 

 inexplicable agglomeration of shapeless matter, they have not 

 been content with observing the extent, the thickness, and 

 the general characters of each bed of stone ; but they have 

 searched diligently for fossils, both large and small — that is, 

 the petrified remains of animals and plants preserved in those 

 old sea-deposits. As the naked eye cannot sufficiently dis- 

 tinguish all the peculiarities of the grains of sand and minute 

 crystals of carbonate of lime, of which a great part of these 

 rocks and stones are composed, so also do we require a 

 lens or a microscope to see in a clay or a limestone all the 

 particles that have originally belonged to animal structures. 

 These organic particles are not always fragments and atoms 

 of bones, of corals, or of shells, but very often are perfect 

 little organisms themselves — perfect shells, perfect cases and 

 coatings of minute animals, or perfect frameworks of micro- 

 scopic plants. 



* See article " Yeast," in ' Black's Cyclopaedia of Agriculture.' 



