THE MICROSCOPE. 247 
and phosphates. The use of the new glass has enabled the manu- 
facturers to materially reduce the spherical as well as chromatic 
aberration, and as a result the performance of the new objective 
is superior to anything yet obtained. 
Mr. Breckenfeldt called attention to some observations of Prof. 
Campbell, of Detroit, in the June number of the American Natural- 
ist on abnormal forms of the fertile part of the alga Vaucheria, and 
exhibited several specimens of that plant, showing abnormal de- 
velopment almost exactly as described by Prof. Campbell. The 
latter surmised that the peculiarities noted were due to the fact that 
the plants collected by him had been kept for some time in rather 
confined quarters; but as the California specimens were found 
growing freely in a large ditch, and were examined immediately 
after being collected, the suggested explanation probably needs 
some modification. 
A paper on “ Aspergillus,” by Dr. Henry Ferrer, was an- 
nounced for the next meeting. 
Avaust 25th, 1886. 
The regular meeting of the society was held at its rooms. Dr. 
Mouser in the Chair. 
A donation of fifty carefully mounted slides of Polyzoa was 
received from Dr. Thomas Porter, of Sandhurst, Australia. The 
Australian coast is peculiarly rich in forms of Polyzoan life, and 
as these slides are authentically named, they will be of great ser- 
vice as aids in determining species of Pacific Coast forms. The 
thanks of the society were unanimously tendered to Dr. Porter for 
his interesting gift. 
Two samples of diatomaceous earth were donated by the State 
Mining Bureau. 
A number of specimens of Teredo navalis, (the ship worm) and 
of Limnoria terebraus, a crustaceous wood-borer, were brought by 
Mr. Manson, who called attention to some interesting questions re- 
garding the food of Teredo—it being asserted on the one hand that 
albuminous sap of the wood bored by that mollusc was assimi- 
lated as food by the animal, while others contend that its food con- 
sists of organisms found in the sea water, and that not only the 
woody fiber but the albuminoids of the sap as well, pass through 
the alimentary canal of Teredo unchanged. Mr. Manson’s remarks 
