Analysis of Hetbeogeneity in Complex Chakacters 249 



primary biotypes. 



In the population of L. muUitceniata I have been able to isolate from the 

 pronotal pattern 13 groups that interbreed, overlap, but can be isolated and 

 which remain constant through an indefinite number of generations. These I 

 have called " primary biotypes," and they can be distinguished as follows : 



Primary biotype 1 — Complete black surface both above and below, without 

 trace of hypodermal color or pattern. (Pig. 35 ; fig. 36, 1.) 



Primary biotype 2 — Spots V, a', am, pm, a, b and anterior marginal spots 

 forming a solid central triangular area. Spots c, e, f, and d and posterior mar- 

 ginal area fused to form an irregular triangular spot in each posterior outer 

 angle. These two larger areas meet along the posterior border in the median 

 line and fuse with the central area through medianward extremes of the d 

 spots. This type may vary from complete fusion of all areas to form a central 

 dark area with a lighter margin (fig. 35, 3) to the extreme shown in figure 36, 3. 



Primary biotype 3 — Differs from No. 3 as follows : The central triangular 

 area is broken anteriorly, traces of anterior marginal spots appearing, and spot c 

 is free from the e-f-g posterior marginal group. As an extreme c may fuse with 

 the lateral group and the anterior spots may by fluctuation give the appearance of 

 a No. 3. Breeding, however, always reveals the real character of the individuals 

 in question. 



Primary biotype If. — Differs from No. 3 and No. 3 in that c is never united to 

 the lateral fused mass of d+e+f, and the anterior ma,rginal spots are never 

 united to the central triangular area and may be much reduced or even not 

 visible, while the central area becomes more open, showing median separation 

 into two lateral a, b groups, which are widely divergent anteriorly. The d, e, f 

 posterior marginal area is also reduced, although still connected and fused 

 usually with the a' b' a h group by a medianward elongation of d, which is 

 deflected cephalward to the anterior end of the a areas. This group is variable, 

 as shown in figure 35, 4, and figure 36, 4. 



The primary biotypes 1 to 4 overlap and form by their " variations " a graded 

 series, as shovm in figure 41, and are distinguished by changes in the relation 

 of the elements of the pattern and not at all by the amount of pigment present. 



Primary biotype 5 — The central spots form a broadly open V composed of 



b'+a' ^- ^a + h. The anterior marginal spots are always entirely wanting 



on all. The posterior marginal d, e, f are fused and d prolonged medianward at 

 90° to median axis, and fuses with a (rarely as a variation; " fluctuation " e is 

 prolonged anteriorly to meet c) . Figure 35, 5, and figure 41, 5, show the char- 

 acter of this biotype. In figure 36 it is shown as forming a diverging line from 

 the meeting-point of the different biotypes and tends to form in appearance a 

 pronotal pattern with a transverse dark band on the posterior half of the 

 pronotum. 



Primary biotype 6 — Precisely the same as biotype 5, except that the anterior 

 marginal spots are always present in varying degree, as are also the posterior 

 marginal areas. The central group is broadly open, as in No. 5, and united to 

 lateral groups in the same manner. In figure 35, 6, this biotype is shown as 

 another divergent group. The tendency of this group is to form a pattern with 

 the posterior half of the pronotum darkened to a greater or less extent. 

 17 



