smaller earthworms from their burrows, even in daylight. Old manure piles, 

 eompost and rotting leaves often harbor several species. If the collector does 

 not care for digging, he may use some of the chemical compounds sold for use 

 on golf courses. These chemicals are soaked into the soil, and often bring up 

 the v^'orms with surprising speed. Worms collected by this method can rarely 

 be kept alive afterward, hov^-ever. 



Care and Preparation of Earthworms 



Worms collected for scientific study are usually kept alive for several days 

 in sphagnum moss or damp cheesecloth or muslin, in order that their intestines 

 may be emptied of soil, Vv'hich might prevent the making of good dissections 

 or the cutting of sections. They arc usually anaesthetised by placing them in 

 water to v^'hich a little chlorotone has been added, or in water to which alcohol 

 is added at intervals until about lO^r is reached. Then, when fully relaxed, 

 they should be washed free of mucus, transferred to fresh 10% alcohol for 

 several hours, then to 40%, 70% and 95% alcohol. After a day or so they 

 may be put in 70% alcohol for storage. If the collector has some technical 

 experience, he will find that injection with 1% aqueous solution of chromic 

 acid following the 10% alcohol bath will produce excellent results. If one 

 expects to section them later, the worms should be transferred from the 10% 

 alcohol to one of the standard fixing fluids, such as Bouin's or Zenker's and 

 the usual procedure followed. 



In the case of some earthworms, unfortunately, the lack of definite ex' 

 ternal characters makes it necessary for one to examine the internal organs in 

 order to determine genera. To accomplish this the worm should be stretched 

 out, dorsal side up, on a piece of soft wood or cardboard, and the skin care 

 fully cut, with fine-pointed scissors, along the mid-dorsal line. The skin can 

 then be turned back on either side and pinned to the board, so that an unob' 

 structed view of the internal organs is possible. 



OUTLINE OF CLASSIFCATION OF WORM-LIKE AND 



LEECH-LIKE ANIMALS 



Phylum PLATYHELMINTHES 



Usually flattened worms without segmentation or body cavity 

 Class TURBELLARIA 



Free-living flatworms with ciliated epidermis 

 Order RHABDOCOELIDA 



With simple tube or sac-like intestine without lateral branches 

 Order TRICLADIDA 



79 



