677 



ENTOZOA. 



EPACRIDACE^E. 



578 



Recently species of Filaria with Monottomata, Distomata, and Infu- 

 toria, have been found in the blood of animals. Gruby and Delafond 

 have found Filaria in the blood of dogs. The results at which they 

 arrived may be shortly stated in their own words as follows : 



1. The number of microscopic Filarias inhabiting the blood of 

 certain dogs may be estimated approximately at from 11,000 to about 

 224,000. The mean number, deduced from 20 does, was more than 

 52,000. 



2. The microscopic Filarice, having a diameter less than that of the 

 blood discs, circulate in the most minute capillaries where the blood 

 discs can find entrance. A drop of blood taken from these vessels, it 

 does not signify at what part of the body, nor at what season of the 

 year, contains these minute Hematozoa. 



3. The chyle and the lymph of dogs, whose blood contains micro- 

 scopic Filarice, present none. 



4. Nor do any of the secretions or excretions. 



5. Nor in the dissection of 28 dogs of different sorts and ages, and 

 whose blood was known to have been verminous for periods varying 

 from several months to more than five years, and made with the 

 utmost care, were any Filarice ever discovered in any of the tissues. 

 Their proper habitat seems to be exclusively in the blood-vessels. 



6. The authors calculate, from the examination of 480 dogs, that 

 the blood in about four or five per cent, is verminous. 



7. It is go more frequently in old and adult dogs than in young 

 ones. 



8. The verminous condition seems to be irrespective of race, sex, 

 or general habit of body. 



9. Even when most abundant, this condition of the blood does not 

 seem to interfere with the instincts or muscular force of the animal. 



10. Noria the constitution of the blood itself altered. 



11. Transfusion of verminous blood, deprived of fibrin, into 

 sound animals, was not followed by any result. But, 



12. When unaltered verminous blood was thus injected, Filaria 

 were found living in the animals experimented on, for more than three 

 years, or until their natural death. 



13. Filaria!, transfused with defibrinated blood into two rabbits, 

 lived in the blood of those animals for 89 days ; after which time 

 none could be found. 



14. In a similar experiment with six frogs, two of which already 

 had Filaria in their blood, the canine Filariie lived for eight days, 

 during the whole of which time the blood-discs of the dog appeared 

 unaltered among those of the frog. On the ninth and tenth days the 

 dog's blood-discs having become changed, the Filarice had disappeared, 

 and the frogs died of a scorbutic malady (!). 



15. Injected together with the blood into the serous cavities or 

 cellular tissue of dogs, in good health, the Filaria: could not live in 

 their new domicile. 



16. A verminous dog, of one race, with a female not so affected, of 

 another, had offspring of which those belonging to the paternal race 

 were verminous, and the others not. 



1 7. When the conditions were reversed, so was the result. 



18. But the Filarice in the blood of the descendants could not be 

 detected till the dogs were five or six months old. 



The authors have also succeeded in finding in the verminous blood 

 of a dog which died in consequence of its being fed exclusively on 

 food composed of gelatine, large worms, visible to the naked eye. 

 They found six, of which four were females and two males, and they 

 were lodged in a large clot occupying the right ventricle of the heart. 

 The worms were white, from 0'5 to 075 inch long, and from 0-039 to 

 0'058 inch in diameter. They propose for this hematozoon, the name 

 of Filaria papilloia lutmatica Canii domestici. 



The Tric/ioccphaliu ditpar, or Long Thread- Worm, is about an inch 

 and a half or two inches in- length, the male being smaller than the 

 female. The capillary portion makes about two-thirds of the whole 

 length of this species. This worm is very common in the cascum and 

 large intestines, but does not seem to occasion any inconvenience, 

 though inflammation of the intestinal follicles and fever has been 

 erroneously ascribed to it The existence and history of the following 

 entozoon are involved in a good deal of mystery. Spiroptera llominu 

 is the name given to some small intestinal worms which were sent to 

 Rudolphi, together with some other vermiform bodies of an elongated 

 form and solid homogeneous texture, which were passed from the 

 bladder of a poor woman then living in St. Sepulchre's workhouse, 

 London. There were also discharged, together with these substances, 

 numerous small granular bodies, considered by Rudolphi as mere 

 morbid concretions, but which subsequent examinations have caused 

 to be regarded as ova. The small nematoid worms, which were six 

 in number, and of different sexes, are supposed to have been expelled 

 from the woman at the same time ; they were from eight to ten lines 

 in length, slender, white, and elastic ; the other elongated bodies 

 varied in length from four to eight inches. Some of the latter sub- 

 ntancea and ova are preserved in the Museum of -the College of 

 Surgeons ; but none of the former Enlozoa, denominated Spiroptera 

 JfiHjtinit, are to be found among them. 



The Ktronrjylut yiyai also inhabits the urinary apparatus. Before 

 Rudolphi'a time it was generally confounded with the Atcarii lumbri- 

 coidtt, to which it bears some resemblance. It occurs, though rarely, 

 in the substance of the kidneys, where it sometimes attains an 



HAT. HIST. DIV. VOL. II. 



enormous size, having been met with three feet long, and half an inch 

 in diameter. The more ordinary dimensions however are about fifteen 

 inches in length and two lines in thickness. The common colour is 

 blood-red, arising from the nature of their food, as they obtain their 

 nourishment from the contents of the renal vessels : they occasionally 

 find their way into the bladder, and are discharged with the urine. 

 This entozoon occurs much more frequently in some animals, as the 

 dog, horse, &c., than in man. Their presence in the kidneys does not 

 seem to give rise to any peculiar symptoms differing from those of 

 other renal diseases. 



The Ascaris Imnbmcoides, the Common Round Worm so frequently 

 met with in children, is so well known as to require a very brief 

 notice here. It occurs in the hog and the ox, as well as in man, and 

 chiefly inhabits the small intestines. The male is smaller than the 

 female, and much more rare ; it may be distinguished by the end of 

 the tail being curved, and terminating in an obtuse point, at the apex 

 of which a small black speck may be frequently observed. In the 

 female this extremity is straighter and thicker. The anus is situated 

 in both sexes close to the tail. In the female there is generally a 

 constriction in the centre of the body where the orgaus of generation 

 are placed. This worm, when minutely examined, will be found to 

 consist of integuments, muscles, digestive organs, genital apparatus, 

 and a nervous system consisting of an cesophageal ring and a dorsal 

 and ventral cord. It has been supposed to feed on the chyle or 

 mucus in the intestines, and to adhere to the coats of the bowels, but 

 on these points there is considerable doubt. They are often found in 

 great numbers. 



The last human species in this group is the Ascaris vermicular!*, 

 the Maw- Worm, Thread- Worm, or Ascarides. It is very minute, the 

 male seldom exceeding two lines, and the female five lines in length, 

 and being proportionally slender. Their colour is white ; they are so 

 small that there is great difficulty in detecting their structure, but 

 Rudolphi says that he has repeatedly observed the three tubercles 

 round the mouth characteristic of the genus. Their abode is the 

 large intestines, particularly the rectum, where they sometimes occur 

 in immense numbers, and occasion great irritation. 



We have now enumerated all the genera of L'/itozoa described by 

 Rudolphi and other entozoologists, but before we conclude our 

 subject we will say a few words on the Trichina spiralis which we 

 have before mentioned. It is a microscopic parasite, infesting the 

 muscles of the human subject belonging to the voluntary class, and 

 found in greater numbers in those that are superficial than in the 

 deep seated. Their nidus seems to be in the inter-fascicular cellular 

 tissue. A portion of muscle affected by these animals appears beset 

 with whitish specks, which, if examined with a microscope, are found 

 to be little cysts containing a minute worm coiled up. The cysts are 

 of an elliptical shape, and attenuated towards the extremities : their 

 length is about ^,th of an inch, and breadth iJoth. By cutting off one 

 extremity of the cyst, the Trichina may be extracted entire, when it is 

 generally found rolled up in two or two and a half spiral coils. 

 Being straightened out, it will be found to measure J,th of an inch in 

 length and fa>th of an inch in diameter. From the minuteness of the 

 object it is necessary to employ a magnifying power of considerable 

 intensity to examine it satisfactorily, and from the difficulty of 

 managing the investigation, and the deceptive appearances produced 

 under the microscope, it is not easy to detect its organisation. 

 Professor Owen never succeeded in discovering an intestinal tube, or 

 cavity, and therefore, as we have stated, placed this entozoou in his 

 first group along with the seminal animalcules. (' Zool. Trans./ 

 vol. i. ; and ' Zool. Proceedings,' February, 1835.) Dr. Arthur Farre 

 observed, by very patient and minute observation with the microscope, 

 under favourable circumstances, that it possesses an intestinal caual 

 with distinct parietes ('Med. Gazette,' Dec. 1835), and upon this 

 ground it ought to occupy a higher station among the nematoid or 

 intestinal worms ; but further researches are necessary before it can 

 be stated with confidence in which group this eutozoon should be 

 placed. It seems that this parasitical affection of the human body is 

 unconnected with age, sex, or any particular form of disease, and it 

 appears that it may exist without giving rise to any debility of the 

 vital powers, or even without interfering with the enjoyment of 

 robust health. 



For an account of the diseases produced by Entozoa, and their 

 remedies, see ANTHELMINTICS, in ARTS AND Sc. Div. 



EOCENE. The lowest of three great divisions of Tertiary Strata' 

 is thus termed by Sir Charles Lyell. [TERTIARY STRATA.] 



EOLID/E. [NUDIBRANCHIATA.] 



EOLIS. [NUDIBRANCHIATA.] 



EPACRIDA'CE^E, Epacrids, a natural order of Monopetalous Exo- 

 genous Plants, very closely allied to Ericaceae, with the small-leaved 

 genera of which they entirely agree iu habit, and from which they are 

 scarcely distinguishable by any character beyond their anthers being 

 in all cases one-celled. Dr. Brown, in founding the order in the year 

 1810, explained his motives for doing so as follows : " The family of 

 Ericeas is now so vast that it seems to constitute a class rather than 

 an order, of which one part, although not a very natural one, has 

 been already separated by Jussieu under the separate name of Jthodo- 

 dmdra, on account of some diversity in the structure of the fruit. I 

 therefore may be allowed to propose another order (Epacridete), which 



2 p 



