47] LIFE HISTOR Y OF TREMA TODES—FA UST 47 



In C. dendritica (Fig. 86) the testes are small, situated closely behind the oo- 

 type. In no case is the ovary clearly differentiated from the region of the 

 00 type. 



The vitellaria are definitely outlined. These glands in C. glandulosa 

 (Fig. 66), C. diaphana (Fig. 78), and C. micro pharynx (Fig. 96) are much more 

 alike than those in the remainder of the stylet species. The vitelline follicles 

 of C. dendritica (Fig. 86), and C. crenata (Fig. 59) are noticeably dissimilar, 

 having on the one hand, a system extending the entire length of the body, 

 and, on the other hand, a system confined to the immediate vicinity of the 

 ootype. 



The genital organs and ducts of C. racemosa, the lateral fin type (Fig. 104), 

 bear some resemblance to those of C. dendritica (Fig. 86). However, Laurer's 

 canal is very prominent in this fintail species, while in C. dendritica it is not 

 so prominent. Instead of coiUng around the right side of the acetabulum, 

 the uterus in C. racemosa makes four double obHque coils dorsal to the acetabu- 

 lum. The ovarian cell mass is dorsal to the ootype and connects with that 

 organ thru a short duct. The testes masses have not been observed. 



2. Echinostomidae. The two species of this group which have been 

 studied, C. trisolenata and C. hiflexa, vary in the structure of their genital 

 organs most markedly. In view of this diversity it does not seem advisable 

 to take them up in detail in this comparative phase of the study. 



3. Furcocercariae. The material of Cercaria gracillima was studied with 

 especial reference to the genital cell masses, both in the totos and the section 

 mounts. The main system consists of the ovary-uterus mass on the right 

 and the cirrus mass on the left, both in the vicinity of the acetabulum. The 

 vitellaria are lateral and empty into the ootype thru transverse ducts (Fig. 149). 

 The testicular follicles are numerous, 24 or 25 having been counted. They 

 are proUferated from a posterior germ mass, which is ventral to the bladder 



NERVOUS SYSTEM 



One of the earlier and better known system of the adult trematode was 

 the nervous system. Leuckart (1863:462) states that Bojanus and Mehlis 

 were famihar with the gross anatomy of the nervous system of the larger flukes, 

 and that von Laurer, Diesing and Siebold as well as the elder van Beneden 

 were acquainted with the nervous systems of both large and small worms. 

 Leuckart described the sy tem for Fasciola hepatica and Dicrocoelium lanceatum-. 

 He states that there are two or three stems, the anterior dorsalis and an- 

 terior lateralis and the thick posterior ven trails. Somewhat later Lang (1880: 

 46-50), substantiates the work of Leuckart and, in addition describes the dor- 

 sal posterior and acetabular innervation. Gaffron (1884) and Looss (1892, 

 1894, 1895) have placed the nerve anatomy of the adult trematode on a 

 firm foundation. Hofmann (1899), Wright (1912), and Monticelli (1914) have 

 confirmed the work of earlier workers. Nor has the finer work on the nerve 

 endings and the ganglion cells been overlooked. Many of the earlier writers 



