205 



or ganglion has progressed considerably and it seems to form a com- 

 pact connection between organ and lobe. 



Fig. 5 shews a more 

 magnified representation of 

 the bulb, part of the olfac- 

 tory pit, and the ventral 

 part of the lobe. It can be 

 seen that the bulb is directly 

 united with the olfactory or- 

 gan through their cells being 

 in contact, but on the other 

 hand there is a small inter- 

 vening space between bulb 

 and lobe, and from their 

 cells a network of nerve- 

 fibres is sent out which con- 

 nects them with each other 

 and fills this space. 



In the last stage that 

 I have examined the development is much more complete. The lower 

 part of the olfactory bulb is thinner and looks like a stem uniting 



Fig. 4. Long. sec. through the head of an 

 emb. of Torpedo ocellata. Stage M, half schematic. 



60/1. 



§^ oW 



Fig. 5. Part of last figure more highly magnified. 250/1. 



