INVERTEBRATE ZOOLOGY. Ill 



lar, but filled with large masses of egg-follicles, giving the whole 

 the appearance of a bunch of grapes. The short oviducts are con- 

 tinuous with these and unite with each other near the median open- 

 ing to form a short vagina. Generally two receptacula seminis situ- 

 ated in close proximity to the median opening. In both sexes the 

 blind ends of the tial)ular germ glands maj' unite, forming a sort of 

 ring. 



84. Development . Egg coccoons. formed by the mother, may be found 

 during the winter upon trees, and in summer among the webs. They are of 

 different species, but may be used indifferently. Examine for winter coccoons 

 any little rolled leaf or bit of leaf attached to the twigs, and look among 

 bushes for large round hanging miasses. The detailed study of the develop- 

 ment requires careful technical maniiiulation, but a general idea niay be 

 gained by studying the eggs with a lens or with the compound microscope. 

 During the early stages the eggs are ojjacjue, biit in later development the 

 growth of the embryo may be seen, the budding appendages, the appearance 

 of the eyes, etc. 



Type XVII. ~A Chilopod (preferably Litliobius). 



85. Collecting and preserving. Myriapods are the "thousand legged 

 worms," found under the bark of decayed stumps, under logs, etc., in damp 

 woods, and occasionally in damp soil. The two orders are distinguished by 

 the legs, one having a single and one a double pair for each somite. Those 

 referred to here [CJiilopoda) have a single pair for each somite and are some- 

 what depressed in form. Alcoholic specimens are sufficient for the work re- 

 (juired here, which is merely the external anatomy. The internal anatomy is 

 verj^ similar to that of insects, and the mode of investigation the same. 



86. External anatomy. Note the well marked segmentation. Is there 

 distinction between body regions? Are the somites differentiated? Is this 

 higlicr or lower than a grasshopper? Study the parts in the following order : 



1. Tlie head. This may be removed from the body and studied in a 

 watch crystal. Be careful not to incli.de the large curved pair of 

 jaws which are reflected upwards and lie over the moiith. They are 

 accessory mouth-parts, but belong to the thorax. The separate ap- 

 pendages may be temporarily mounted for special examination. 

 The eyes are small masses of simple eyes (ocelli) on the sides 

 of the head. One i)air of antennae. Mouth parts consist of mandi- 



