The cases which had occurred before the puhlication of the first description of this Entozoon led me to conceive that, although the species was of so minute a size, yet the num ber of individuals infesting the body was so immense, and their distribution through the muscular system so extensive, that they might occasion debility from the quantity of nutri ment required for their support ; and I ob served " that it was satisfactory to believe, that the Trichina: are productive of no other con sequences than debility of the muscular system; and it may be questioned how far they can be considered as a primary cause of debility, since an enfeebled state of the vital powers is the probable condition under which they are originally developed. No painful or incon venient symptoms were present in any of the above-mentioned cases to lead the medical attendants to suspect the condition of the mus cular system, which dissection afterwards dis closed : and it is probable that in all cases the patient himself will be unconscious of the presence of the microscopic parasites which are enjoying their vitality at his expense."
Since writing the above, a case has occurred in which the Trichinw were met with in the muscles of a man who was killed while in the apparent enjoyment of robust health by a frac ture of the skull. I received portions of the muscles of the larynx of this individual from my friend Mr. Curling, Assistant-Surgeon to the London-llospital, who has recorded the case in the Medical Gazette, and the worms were similar in every respect to those occurring in the diseased subjects. The deduction there fore of the development of the Trichina being dependent on an enfeeblement of the vital powers is invalidated by this interesting ex Leaving now the consideration of Entozoa, which from their minute size and organization would have ranked with the vast assemblage of animalcules which are collected under the head inliisuria in the ltbgne Animal, we come next to the consideration of the animals which form that scarcely less heterogeneous class, the Entozoa of Itudolphi. These are distributed by that Naturalist into five orders, which may be synthetically arranged and characterized as follows.