DIGESTIVE SYSTEM 115 



numerous strands of connective tissue. Their ducts, 

 which are long and slender, run forwards and open 

 into the buccal mass, one on each side of the 

 oesophagus. 



2. The liver is a very large bilobed gland, of a reddish- 

 brown colour, which forms a large part of the visceral 

 hump. 



a. The right lobe of the liver is the larger of the 



two, and is partially subdivided into three lobes. 

 It lies in the upper half of the first turn of the 

 spire, immediately behind the mantle-cavity, and 

 is grooved on its outer surface by the intestine. 

 It has three main ducts, which unite to open by 

 a single large aperture into the right side of the 

 stomach. 



b. The left lobe of the liver is lodged in, and almost 



completely occupies, the second and upper turns 

 of the spire. It is separated from the right lobe 

 by the posterior end of the crop, the stomach and 

 the commencement of the intestine, and the 

 albumen gland. It has one large duct, which 

 opens into the left side of the stomach, almost 

 opposite to the right duct, but slightly beyond it. 



Slit up the stomach, and wash out its contents. Note the 

 openings of the bile-ckicts, and follow these with a seeker into 

 the lobes of the liver. 



IV. DISSECTION OE THE EEPEODUCTIVE SYSTEM. 



The snail is hermaphrodite, but does not fertilise its own 



ova. As is usual ia such cases, the reproductive organs are 



extremely complex. 



1. The hermaphrodite gland is a small yellowish body 



lying on the inner side of the second turn of the 



spire, and closely imbedded in the left lobe of the 



liver. Within it both ova and spermatozoa are 



produced. 



i2 



