PLATE 20 



EXPLANATION OF FIGURES 



129 and 130 Stages of the growth of the rudiments of the midgut of 

 Pseudococcus. 



131 Longitudinal section of an Iceryan embryo a short time after the com- 

 pletion of revolutions. 



132 Longitudinal section of an Iceryan embr3ro like the one represented in 

 figure 119. 



133 The colony of symbiotic parasites at the time of the hatching of larva. 



166 



