288 DR BENNETT ON THE PARASITIC VEGETABLE STRUCTURES 



Alytes obstetricans, similar to those which grow on the eggs of fishes. HANNOVER of 

 Copenhagen 1 observed confervse growing on the living salamander (Triton puncta- 

 tus) when the tail was partly cut off, or the spinal cord divided so as not to occasion 

 death. They sprung from the surface of the wound, and spread more or less over 

 the integuments. Examined with the microscope, they were found to consist of 

 membranous, simple, very seldom or never branched tubes, with corpuscular con- 

 tents. The tubes varied in thickness, were conical at then* extremities, but some- 

 times swoln and bulbous. There was often present a cellular formation, either 

 springing from the walls of the tube, or from regular notches in the sides. Some- 

 times the tube was full, at others almost empty, the latter generally when the 

 confervse were ripe, and then they hung on the outer side of the tube. 



STILLING" of Cassel saw similar confervse on the toes of frogs, when the 

 greater part of the inferior half of the spinal cord had been removed. From the 

 first appearance of the efflorescence the animals, previously lively, became evi- 

 dently weak, and made very slow movements. STILLING considers this structure 

 to be of an animal nature. The granules contained in the cells possess move- 

 ments, and he conceives them to be ova, from which small infusoria issue. He 

 thinks the tubes are albuminous or fibrinous, and serve as a nidus in which the 

 ova become developed. He states further, that the cellular structures which have 

 been perceived in these tubes are Vorticellse, and that he has seen them burst and 

 discharge their contents. 



I have often seen similar animalculse to those described by STILLING in fluids 

 which have become putrid by long contact with animal matter. They are often pre- 

 sent without any trace of vegetation, so that the latter are by no means necessary 

 for their existence. I think that he is in error in supposing that the granules are 

 ova ; that the dichotomous branches are composed of albumen or fibrin ; or that 

 the cellular structures are vorticellse. The granules, tubes, and joints are, in my 

 opinion, in every way analogous to those found in vegetable structures. That 

 animalculse may occur within them, as well as in the surrounding fluid, there can 

 be no doubt, but their appearance is a subsequent phenomenon. 



This opinion of mine is confirmed by more recent observations of HANNOVER. S 

 According to him, the movements described by STILLING in the contents of the 

 cell, are of a molecular nature. He denies that they are the eggs of infusoria, 

 and points out that the larger worms described by STILLING, are ascarides from 

 the intestines of the animal. In this memoir, also, he minutely details the mode 

 in which the plants are developed. 



1 MULLER'S Archives, 1839, p. 338. 



- Idem. 1841, p. 279; and Lend, and Edinb. Month. Journ. of Med. Science, October 1841. 



3 MULLER'S Archives, January 1842. 



