Meandering Cells 



39 



have been observed within them, and they appear to 

 undergo very slow amoeboid changes. Such cells, adherent 

 to the inner face of the epidermis, have been found also in 

 the blow-fly larva ; they are the wandering cells (Wander- 

 zellen) of Metschnikoff and Kowalewsky ^ From the 

 various states of aggregation which these cells exhibit, 

 and from their slow change of figure, it is probable that, 

 like the corresponding cells of the blow-fly, they can 



Fig. 30. — Third abdominal segment of larva and parts of two others laid open 

 from above. In the middle line is the nerve-cord with tlie fourth and fifth 

 abdominal ganglia, and paired nerves passing to the body-wall. In front of 

 each ganglion a transverse nerve crosses the nerve-cord. The recti ventrales 

 muscles lie next to the nerve-cord, and outside these are the transverse and 

 oblique muscles. A pair of groups of oenocytes are also seen. 



move from place to place, and that, however they may be 

 scattered, they retain the power of combining into an 

 epithelium. The blastoderm of many insect-embryos is 

 formed out of cells which previously moved about in 



' Metschnikoff, 1885 ; Kowalewsky, 1887, pi. xxvi (fig. 4). 



