12 OYSTER BOTTOMS IN VICINITY OF APALACHICOLA, FLA, 
culture. In many cases different observers will not agree as to the 
proper term by which to describe the bottom so tested, and it is there- 
fore difficult to convey to another the meaning desired. To overcome 
this difficulty an instrument @ has been devised which gives these data 
mechanically, by measuring the number of inches the bottom is 
penetrated by a plunger of a constant weight and size fallmg through 
a uniform distance. The mstrument is used from an anchored boat, 
from 6 to 10 tests being made at each station, Any readings which 
are markedly higher or lower than the others are discarded on the 
assumption that the plunger has fallen mto a crab hole or other 
depression, or that it has encountered a shell or similar accidental’ 
obstruction. The average of the remaining depths of penetration, 
as indicated on the scale of inches inscribed on the rod, is regarded 
as the measure of the consistency of the bottom. 
The following designations used to indicate the different degrees ° 
of hardness, as shown by the instrument, are arbitrary, although 
based on the terms used by the oyster growers: 
I BUG Wo bob pert di es Ae: der th pcan rl den tos St ct emi Og ote Penetration less than 4 inches. 
Sir age e eee MM Cle Mees REIS Sh ome Adee DAs ee es Penetration between 4 and 8 inches. 
Soft Pee rks a Pee ks Cees or Mee Penetration between 8 and 13 inches. 
Wery, Soft oc 2° tae tcted speak Peeps) oe eo ceteris 2 t Penetration between 13 and 18 inches. 
OO Ze oe. 2c See el aes ag itl Li eg uit AipaS Penetration over 18 inches. 
These various types of bottom are shown on the chart by means of 
circles, the relative area of black included within them indicating 
the relative degree of hardness, as follows: Hard, a black circle; 
stiff, a black semicircle; soft, a black quadrant; very soft, two cross- 
ing diameters; ooze, one diameter. 
The bottoms classed as hard and stiff, those in which the plunger 
will not penetrate more than 8 inches, are suitable for planting 
without preparation, provided they are not composed of shifting 
sand, As sand invariably gives a reading of less than 4 inches, and 
is therefore rated as ‘‘hard,” it follows that all ‘‘stiff’’ bottom shown 
on the chart by a black semicircle can be accepted as safe for planting. 
Part of the hard bottom is composed of mud and part of sand. The 
former may be accepted without hesitation, but the latter should be 
examined with respect to its liability to shift. Soft bottom should be 
planted with care, and toward its upper or less consistent limits may 
require some preliminary hardening with shells or sand. Very soft 
bottom and ooze should not be considered, as oysters planted there 
will smk, and if not killed, as is probable, will be ill-shaped and 
inferior in every respect. The ratings on which the classificationis 
based have been checked by observation on bottoms actually used 
for oyster culture in Chesapeake Bay. 
a Illustrated and described in “Condition and extent of the natural oyster beds and barren bottoms 
of Mississippi Sound, Alabama.”” By H.F. Moore. Bureau of Fisheries document no. 769. 
