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illustrations of the origin of species by degeneration. For it is 
well to bear in mind the words of Herbert Spencer, “ Evolution 
does not imply as commonly conceived an intrinsic tendency in 
everything to become something higher.” 
I am indebted for information to the publications of the 
following authorities: Dr. A. Giinther, F.R.S., Professor Ray 
Lankester, F.R.S., Professor Huxley, F.R.S., Professor Rupert 
Jones, F.R.S., and Professor Ernst Haeckel. I wish to express 
my obligations to Mr. B. Lomax, F.L.S., for the beautiful and 
accurate enlargement (after Haeckel) of the anatomy of an 
Ascidian, which will be placed in the Museum, as it is almost 
impossible to obtain or exhibit specimens of such a perishable 
nature, and excellent diagrammatic representations of them are 
most useful for the instruction of students. 
WEDNESDAY, MAY 7Tu, 1889. 
DR. NEWSHOLME 
(MEDICAL OFFICER OF HEALTH FOR BRIGHTON), 
ON 
SOME PROBLEMS OF POPULATION. 
The laws regulating the number of the human species formed 
a most complex and perplexing subject. In a general study, it 
would be well to consider :—(1) The past progress of the English 
population ; (2) Urbanization and its sanitary and social effects ; 
(3) The effect of improved sanitary condition on the population 
problem ; and (4) The limits to the increase of the population. 
There was no census before 1801, but in the 14th century 
the population of England and Wales was estimated at two and a 
half millions ; and at the same number in the 16th century. In 
1700 it had risen to 5,475,000, and in 1801 to 8,892,536; thence 
rapidly increasing to 25,974,489 in 1881. If, instead of accepting 
actual enumerations, one took the increase as determined by the 
excess of births over deaths, the effect of migration would be 
eliminated ; and that this natural increase varied greatly in 
different countries was shown by the fact that, taking the excess 
of births over deaths, England and Wales would double itself in 
7. Ta 
