24 



The Philippine Journal of Science 



1916 



The second chain is longer; it is composed of twenty-three 

 segments, which are larger than those of the first. The head is 



missing, but a part of the neck re- 

 mains. The chain measures after 

 staining 72 millimeters, and the 

 largest segment is 7 millimeters by 

 2 millimeters. 



The third chain is 2 centimeters 

 long, has no head nor neck, but one 

 end of it is finer and has smaller seg- 

 ments than the other end. 



The last chain is composed of five 

 segments and measures 11 milli- 

 meters in length after staining. 



These parasites are placed in the 

 museum of the College of Medicine 

 and Surgery, University of the Phil- 

 ippines (No. 1495). 



BIOLOGY OF THE PARASITE 



This worm is a parasite of car- 

 nivorous animals, accidentally of man 

 and especially of children. It has 

 been classified under Cestoda, family 

 Hymenolepididse, subfamily Dipyli- 

 dinse (i) and the description of it has 

 been fully given by C. W. Stiles. (2) 

 The adults are normally found in 

 the intestines of small dogs (Canis 

 familiaris) and cats {Felis catis) in 

 great number where they grow rap- 

 idly. The ripe proglottides are so 

 active, as shown in this case, that 

 they can pass by their own move- 

 ments through the anus of the host 

 with the faecal material. Usually the 

 segments are isolated and few, al- 

 though a great number can come out. 

 As soon as they are out of the anal 

 ring, they crawl toward the hairy 

 parts of the skin, where they deposit 

 their eggs, which are swallowed by the dog louse (Trichodectes 

 canis), or cat louse (T. rostratis Nitzsch), or are aspirated by 

 the dog flea {Ctenocephalis canis Curtis), cat flea (C. felis 



Fig. 3. Posterior segments of Dipy- 

 lidium caninum. u, uterus ; t, tes- 

 ticles ; vd, vas deferens ; cp, cirrus 

 pouch ; c, cirrus ; v, vagina ; ov, 

 ovary ; rs, receptaculum seminis ; 

 vg, vitelline gland. 



