INTRODUCTION. Ixiii 



cyst ; but, according to Joliet's views, they originate in 

 the endosarc that is, in the very tissue which supports 

 and invests the brown body. 



The following points may be taken as established : 

 i. The brown body is universally derived from the substance 

 of the histolyzed polypide. ii. It is always attached (when 

 occupying its original position) to the funiculus, and more 

 or less invested by the funicular plexus, iii. Buds for 

 the production of a new polypide are very commonly de- 

 veloped in the closest proximity to it and on its surface, 

 iv. They also originate in various positions, and at greater 

 or less distances from the brown body. v. In some spe- 

 cies the latter is enveloped by the neighbouring bud, and 

 passes into the digestive canal, being ultimately expelled 

 through the intestine, either entire or after having under- 

 gone dissolution in the stomach*. vi. There may be 

 several brown bodies in a cell ; and in some cases they 

 lie loose in the perivisceral cavity near the bottom of it 

 (Farre). 



On the whole, and especially taking into consideration 

 the later observations to which I have more particularly 

 referred, I must admit that the evidence at present tallies 

 better with the residuary theory of Nitsche and Joliet than 

 with the reproductive theory of Smitt. At the same time 

 I must also hold that no satisfactory explanation has yet 

 been offered by our critics of the very precise observations 

 of Smitt and of my own. There seem, therefore, to be 

 grounds ( pro tantd) for desiring some further investigation 

 of the subject. 



* I must allow that it is improbable a priori that the same body would 

 be in some cases an important reproductive factor in the colony, and in 

 ..li.-r- would be ejected as mere rubbish by means of a special arrangement. 



