INDUSTRIAL PROGRESS DURING THE YEAR 1873. xcvii 



lower Vermes ; while from their later divergence the fixed 

 and cephalized Annelides are more closely allied to the pres- 

 ent free Chaetopods. The facts, whatever some may think of 

 the author's conclusions, are mostly new, and presented by 

 the author with great skill and interest, while many natural- 

 ists will believe that Professor Morse has demonstrated the 

 worm- like nature of these animals. A second memoir, in 

 quarto, on the embryology of our common Brachiopod, the 

 Terebratulina^\^2L^ subsequently appeared in the "Memoirs of 

 the Boston Society of Natural History," which goes to con- 

 firm the worm origin of these animals. Brief papers relating 

 to the classification of the Brachiopod s have been published 

 by Professors King and Gill, and Mr. Dall. 



Further contributions to the minute anatomy of the Tcenice, 

 or tape-w^orms, have been made by Dr. Nitsche, and appear 

 in Siebold & KoUiker's celebrated journal, while a resume 

 of Dr. Krabbe's work on the tape-worms of birds appears in 

 Gervais' 7bi'^a7 cle Zoologie. It seems by his account that 

 more than half of the known species of these Cestoid worms 

 inhabit birds; the number of known species of Cestoids 

 amounting to over 300. The tape-worms are naturally more 

 abundant in the aquatic birds, which prey on fish, than the 

 land birds, while they are less abundant in the birds of prey 

 and the graminivorous birds, which is the more remarkable be- 

 cause they especially favor the carnivorous mammals. While 

 Ktichenmeister has found that the Cysticercus of the slug 

 (Zfimax) transforms into the Tmnia of the common European 

 sandpiper. Dr. Krabbe has found that the young of the Tmnia 

 of the heron is an animal found in the tench, and described 

 under a different name by Nordmann. Dr. Cauvet contrib- 

 utes a notice of the Tmnia (T. medio canellata) so abundant in 

 the French army in Algeria. 



Further observations have been made on the sin2:ular met- 

 araorphoses and habits of the Trematode worms. O. von 

 Linstow decides that there must be two modes of transport 

 of the young Distomum, or Cercaria-form, into the bodies of 

 fishes. In the 'first case the fish eats a snail {Paludina) con- 

 taining encysted Cercarim; the Cercarim are set free by the 

 digestion of the cysts, and attain their sexual state in the in- 

 testine of the fish. In the second case the fish {Acerina cer- 

 nua) eats a molhisk containing free Cercarim^ or else these 



5' 



