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by the strueture of the proximal part of the femurs which are 
divided by a groove into a short proximal and a long distal part, 
forming an obtuse angle with each other, so that the distal part is 
directed moré upwards. This is much more prominent in the first 
pair than in the others, where it is more or less indistinct. The 
difference between the legs in this respect can be explained by the 
special funetion of the first pair. The articulations between the 
femur and the patella and tibia are ginglymous articulations with 
the main direction downwards. The patella, whieh is always shorter 
than the tibia, serves to change the more or less perpendicular 
direction t0' one approaching the horizontal. The tibia serves to 
change the direction to a more or less perpendicular one, .so that 
the tarsus may reach the ground. The articulation between the 
tibia and the metatarsus is more universal than the last named, as 
it permits movements in several directions; this is most prominent 
in the first pair of legs. The articulation between the metatarsts 
and the tarsus of the first pair of legs is very little developed, 
while the corresponding oné in the last three pairs resembles the 
articulation between tibia and mesatarsus of the first pair. 
If the first and the last pair of the legs be compared with 
each other, it might perhaps at first sight seem natural to identify 
the proximal part of the first femur with the trochanter second of 
the fourth pair. But when we observe that there is no articulation 
between the two parts of the first pair of femurs and that the 
articulation between the trochanter and femur is a ginglymous one, 
while the one between the trochanter first and second is universal, 
and last but not least that also the trochanter second is. undivided, 
there can be no doubt about the homology between the trochanter 
I and the two trochanters IV. Add to this that the last pair of 
femurs show vestige of 'a proximal femoral part (pl. V fig. 1—5). 
Leg I (pl. V fig. 1). The relative length between the joints is 
different from that of the last three pairs. The coxa is short, almost 
round, and provided with few pointed hairs below. The trochanter 
(fig, 1 a) is almost cylindric and three to four times as long as high. 
