28 Journal of Entomology and Zoology 



droids. In the last of November of the same year not a single 

 larva, immature form or adult, was found although a very thor- 

 ough search was made of the surface and interior of the polyps and 

 ciead stems. 



Figs. 1, 2 and 3 are drawn to the same scale, X350. In Fig. 6, 

 a number of stages from the egg to the latest larval stage is 

 shown, all drawn at the same scale. Stage b probably moults upon 

 entering the polyp; as judgeci from the cast skins, there is probably 

 a moult between c anci a, and d and e. As shown in Fig. 3, there 

 are little knobs left just ahead of the limb buds. These knobs are 

 the vestiges of the whip-like appendages of the earlier stage. 

 According to Semper these two appendages degenerate com- 

 pletely, Adlerz believes that some vestiges of these remain and in 

 their place the second and third limbs of the aciult are formed. 

 Meinert believes that the second and third appendages of the larva 

 entirely disappear and the palps and ovigers are new structures. I 

 am sure from the examination of many embryos of J. erectus that 

 the larval second and third appendages disappear beyond recogni- 

 tion and that the ovigers develop after the animal is almost an 

 adult, but I am not sure that the little knob which may be seen in 

 parasitic and later stages does not represent the ovigers. If this 

 last be true, it Avould be very difficult to prove that it was an entirely 

 new structure, because it grows out from the place where the third 

 larval organ disappears. The chelifori of the larval stages are 

 continued directly to the adult condition. Very little of the internal 

 structure is shown from the surface of the earliest stages. The 

 nervous system is not shown as a distinct area in earliest larval 

 stages although it is well shown and well developed in the similar 

 stages of other larvae. It may be that the probable lack of activity 

 may not necessitate the sharp demarkation of the brain and ganglia. 

 Later parasitic larval stages show well-marked ganglia for the 

 larger appendages and smaller ones for the caudal and cephalic 

 ends. At the caudal end there seems to be a gradual development 

 of the ganglia with the development of the caudal end of the animal 

 and in some free living forms there seem to be at least two pairs 

 of ganglia beyond the thoracic or leg ganglia. At the cephalic end 

 it is more difficult to make accurate observations. In parasitic 



