20 PROGRESS OF MICROSCOPICAL SCIENCE. 



the racthorl employed for filtering the air through water. The usual 

 method has been to place a small quantity of pure water in a large 

 bottle, and shake it in the air imdcr investigation, rej)eating the 

 operations with renewed volmnes of air in the same water ; but Mr. 

 Stodder shows how impossible it is to intercept all the foreign par- 

 ticles in the atmosjihere in this way, inasmuch as the smallest bubbles 

 of air which pass through the water very much exceed in size the par- 

 ticles of matter which are sought for, and myriads must elude observa- 

 tion. A gi-eater difficulty, however, is to obtain absolutely pure water 

 for such experiments ; and whether filtered or distilled water was 

 used, a di*op evaporated on a glass slide always left a deposit of scaly 

 and granular particles. This result, as Mr. Stodder justly says, puts 

 an end to this mode of investigation, and throws a cloud of suspicion 

 on all reported researches in this line, when water was the medium 

 used. 



Description of new Genera and Species of Australian Polyzoa. — 

 Mr. P. H. Mac-Gillivray, M.A., read a paper on the above subject 

 some time ago before the Eoyal Society of Victoria. Still, as the 

 journal containing the paper only reached us a couple of months since, 

 we tliink the subject may be new to some of our readers. In this 

 paper are given descriptions of forty-eight sj)Gcies, including two 

 genera, of Australian polyzoa, which cannot be satisfactorily referred 

 to any of those hitherto described. The identification of polyzoa by 

 the aid of descriptions alone, however accurate these may be, is often 

 extremely difficult. The species here described, as well as the others 

 existing in Victoria, will be figured in Professor M'Coy's ' Memoirs of 

 the Museum,' where Mr. Mac-Gillivi-ay hopes to be able to give 

 descriptions of all those with which he is acquainted. Specimens 

 will also be deposited in the National Museum. He has added a list 

 which contains all the Victorian species he has in his collection, with 

 the exception of a few not yet determined. The descriptions then 

 follow, but are far too numerous for our space. See Reports of the 

 Royal Society of Victoria. 



The Tissues of Man and Apes. — Dr. Lionel Beale, P.R.S., imagines 

 that there are material differences between the tissues of man and 

 apes, and he calls on naturalists to investigate them. In a very able 

 and lucid address to the Quekett Club, he says : — " It is wonderful 

 what haphazard assertions are made in these days concerning the 

 likeness or identity of dissimilar things. Observers, who should test 

 these assertions, and ascertain whether they are accurate or not, 

 permit them to pass without comment, and the public accejits them 

 as literally true. We are told, for example, by Mr. Darwin, that it is 

 ' scarcely possible to exaggerate the close correspondence in general 

 structure, in the minute structure of the tissues between man and the 

 higher animals, especially the anthropomorphous apes.' But Mr. 

 Darwin does not tell us that he or anyone else has made the obser- 

 vations upon which the statement is founded. A careful comparison 

 of the tissues of man with the corresponding tissues of apes in 

 minute structure is much to be desired, but it has never been made, 

 and it is quite j)rematurc to speak of the supposed ' close correspond- 



