138 



Mr. K. Kunhi Kannan on 



The antennal variability in these two forms is very great 

 and is disclosed by the following analysis : — 



Long Form (of 33 examined). 

 Antennae 8&8 segmented in 16 



Round Form (of 25 examined). 



Antennae 8 segmented in 15 



S&7 „ 3 



8&6 „ 1 



7&7 „ 1 



6&6 „ 3 



6&5 „ 1 



5&5 „ 1 



From this it appears that among the round form, of the 

 25 examined 10 had abnormal antennae, or 40 per cent. 

 In the long form of 33, 17 had antennal abnormality, or 

 51*5 per cent. The range of variation as shown in the 

 charts (PI. VII, figs. 1 and 2) is very great and far exceeds 

 the limits of ordinary variation. It is not alone that 

 segments show a reduction in number and relative length, 

 but in the same specimens the antennae may be different 

 in the number and relative length of segments, producing 

 an asymmetry. The variability in size, colour, shape and 

 elevation appears to continue to the same extent in the 

 specimens sent by Prof. Keuchenius in 1916 as when he 

 studied the pest two years previously. 



Between these two varieties described above, there are 

 several intermediate forms, presenting several stages and 

 gradation in details of structure, size, colour, elevation 

 and conspicuousness of the loop, but they are mainly 

 grouped round these two types. From a study of the 

 material the impression is forced on one that the Javan 

 forms are highly unstable. Two of these forms described 

 above are entitled to specific rank. One of these, the oval 

 flat form, may prove identical with the new form described 

 by Mr. Newstead as Coccus africanum. The other lias, 

 so far as I am aware, not been described. I refrain from 

 creating species for the reception of these two, until I 

 have an opportunity to examine Coccus africanum. 



These facts of variation prove that Coccus viridis is a 

 mutating species. In Mysore the bug was all but caught 

 in the act. and in Java the saltatory variations continue. 

 In Uganda a new form has been in existence since L898, 

 when C. africanum was first described as a subspecies. 



There are two views possible in regard to this interest ing 



