6 
Psyche 
[March-June 
variations of the connection were not due to the amount of time 
which elapsed between slide preparation and exposure of the negative 
was shown by comparing photomicrographs with the slides after more 
time had elapsed. After several weeks to a year, essentially no 
changes in structure were discovered except for frequent disappear- 
ance and fusion of globules on the sticky spiral. 
Various measurements and counts were made from the negatives 
and prints. Since i [i was close to the limit of resolution on the 
photomicrograph, measurements in this range should be considered 
approximations. The thickness of a thread associated with a con- 
nection was usually measured at a distance of 150 /x from where 
the thread joined the other thread. In most cases, threads were 
fairly uniform in thickness at this distance. Closer to the other thread, 
thickness had a greater tendency to vary, and measurements were 
complicated by features of the connection. When the thickness of 
a thread at 150 /x was obviously not typical for that thread, as for 
example, when a sticky spiral had a globule on it at this point, the 
thickness was measured somewhat further from the connection. 
When strands were counted at a connection, “separate strands” 
were defined as strands with a visible space between them in the 
photomicrograph. However, sometimes an estimation of the number 
was used because some strands were hidden by others, and some 
were out of focus. 
The reader may refer when necessary to the following list, in 
alphabetical order, of abbreviations which will be used in this paper; 
FY, frame Y-structure; NS, loop of non-sticky spiral from the 
strengthening zone; NS-R, non-sticky spiral to radius connection 
from the strengthening zone; PS, loop of provisional spiral; PS-R, 
provisional spiral to radius connection; R-F, radius to frame connec- 
tion; RY, radial Y-structure; SS, loop of sticky spiral; SS-R, sticky 
spiral to radius connection. 
RESULTS 
The microscope reveals a wealth of structural detail at thread 
connections from which many component features can be abstracted, 
and the complexity and variability of which make description difficult. 
Some features of the structures will be pointed out in the following 
sections; and sample photomicrographs will be presented. Various 
descriptive statistics (percentages, means, coefficients of variation, 
and ranges) will be used to provide an impression of the prevalence 
of certain features and the central tendency and variability of meas- 
