40 H. W. MARETT TIMS. 
to me from the Marine Laboratory at Millport, as well as a 
specimen of Gadus argentina kindly given to me for 
examination by the late Professor G. B. Howes, F.R.S. 
From my own experience and from the expressed opinion 
of other workers in the same field, a succinct account of the 
earlier literature is a much needed desideratum, and this 
I have endeavoured to furnish, the more recent and generally 
known papers being omitted. 
HISTORICAL. 
The first to note the presence of markings on the surface 
of the scales of fish was Petrus Borellus in 1656 (2). He 
thus describes them in ‘Observatio,’ xxxvii (p. 23): 
“Squamz piscium apparent si aspiciantur, lineis orbicularibus 
multis distincte, et in parte qua cuti adherent radiis ac 
punctis multis transcurrentibus eas divisa.” In his accom- 
panying illustrations he figures these lines and points over 
a limited area of the scale only, which is quite in accord with 
the condition found in some scales, though he makes no 
reference to this point in the text. ‘his observation is 
of interest as being one of the earliest results of microscopic 
investigation. Nine years after this (1665), R. Hooke (10) 
published still further details upon the same subject. He 
seems to have investigated the matter from a more compara- 
tive standpoint, for though he describes the scales of the sole 
and dog-fish only, giving illustrations of the former, he says 
he has examined the scales in “ multitudes of others, which 
it would be too long to enumerate.’ This early account of 
their structure is sufficiently interesting to merit quotation. 
He writes (p. 162): ‘This skin I view’d, was flead from a 
pretty large Soal and then expanded and dry’d, the inside of 
it, when dry, to the naked eye, look’d very like a piece of 
Canvass, but the microscope discovered that texture to be 
nothing else, but the inner ends of those curious Scolop’d 
Seales, which on the back side, through an ordinary single 
magnifying glass, look’d not unlike the Tyles on an house. 
