1156 
he means the brownish tint of part of the light spots, as seen for 
example in Oxyna parietina, — where a certain number of spots, 
localised in the broad dark transverse bands, differ from the rest 
of the spots between these bars in a yellow brown shade as well 
as in smaller size, — 1 cannot agree with his distinction of two kinds 
of spots. For in other species of the genus Oxyna, I see in the same 
localities similar spots, differing only in so far as they possess the 
usual hyaline aspect and are not smaller than, or in any other way 
distinct from their companions in the interspaces between the bars 
Therefore I cannot consider the “Tüpfelflecke” themselves as an 
addition to the pattern, but only their hue and diminutive size as_ 
secondarily acquired properties, which, far from leading to the 
evolution of new spots, on the contrary contribute to the disappearance 
of existing spots. 
Groningen, March 30 1917. 
Zoology. — “On the Setal Pattern of Caterpillars.’ II. By 
Dr. A. SCHIERBEEK. (Communicated by Prof. J. F. van BEMMELEN). 
(Communicated in the meeting of March 31, 1917). 
In a former communication’) | called attention to the constant 
arrangement of setae on the body of caterpillars, and I gave the 
reasons which induced me to propose a new nomenclature for these 
setae, representing them in a set of schematical figures. 
My investigations led me to the following conclusions: 
1. setae (bristles), tubercula (eminences bearing setae), verrucae 
(warts), scoli (spines) and maculae (pigment-spots) are all of them 
homological structures. 
2. the abdominal segments possess a setal pattern of more primi- 
tive arrangement than the thoracic. 
3. the system of bristles which | have designated as type I is 
the most primitive, the remaining types (Ia, I, II) may be derived. 
from it. 
4. changes occurring in type I possess a definite systematic value. 
5. stripes have developed at a later date than pigment-spots. 
6. the design of the pupa shows the nearest resemblance to that 
of the first larval instar, but often deviates considerably from that 
of the last one. 
1) A. ScrierBeeK, On the Setal Pattern of Caterpillars. Proc. Roy. Acad. Sc. - 
Amsterdam. Sect. 2, Vol. XXIV. p. 1710—1723; March 25, 1916. 
