Group II
In the first figure (a) of figure 54 that contains members of Group II the wings are almost entirely absent or "vestigial". This condition arose at a single step and breeds true, although it appears to be influenced to some extent by temperature, also by modifiers that sometimes appear in the stock. Purple
eye color belongs in Group II; it resembles the color of the eye of the wild fly but is darker and more translucent.
In the second figure (b) the wing is again long and narrow and sometimes bent back on itself, as shown here. In several respects the wing resembles strap (d) but seems to be due
to another factor, called antler, insufficiently studied as yet.
In the third figure (c) the wings turn up at the end. This is brought about by the presence of the factor called jaunty.
In the fourth figure the wings are long and narrow and several of the veins are unrepresented. This character, "strap", is very variable and has not yet been thoroughly studied. On the thorax there is a deep black mark called trefoil. Even in the wild fly there is a three pronged mark on the thorax present in many individuals. Trefoil is a further development and modification of this mark and is due to a special factor.
In the fifth figure (e) the wings are arched. The factor is called arc. The dark color of the body, and especially of the wings, indicates the factor for black.
The sixth figure (f) shows the wings "curved" downwards. In addition there is present a minute black speck at the base of each wing, due to another factor called speck.