Miscellaneous. 429 



is recorded in M. Ch. Morren's Report on the Exhibition of the pro- 

 ducts of Belgian agriculture and horticulture, 1847. — Bibliotheque 

 Universelle, Feb. 1850. 



On the Nature of the Gregarinse. By Dr. F. Stein. 



The author has raised the number of species of insects in which 

 Gregarinte occur to 68. Previously it was known only of 29. With 

 the addition of the Myriapoda, Crustacea and Annelides (the Lum- 

 brici contain some in their male organs ; Henle), the number amounts 

 to 80. They are for the majority voracious and carnivorous animals ; 

 at all events they never feed upon fresh vegetable matter. This dis- 

 tribution of the Gregarince in species whose kind of life is so exclusive 

 evidently proves that their germs are introduced with the food. 



The body of the Gregarince is an ovoid, fusiform or cylindrical sac, 

 everywhere closed, without any trace of mouth or anus. In some 

 species the body is simple, but most frequently it is separated into 

 two parts. The anterior portion forms a hemispherical or conical 

 segment, separated from the remainder by a strangulation. A verti- 

 cal septum corresponds to this constriction, and thus divides the in- 

 terior cavity into two portions. This septum had not been previously 

 observed. In other species the body is divided into three cavities by 

 two strangulations and two corresponding internal septa. 



In accordance with these differences of organization, the author 

 separates the Gregarince into three natural families : — 



1 . The Monocystidece or simple Gregarince, without strangulation 

 and without internal septum. 



2. The Gregarinariece, or ordinary Gregarince with the body di- 

 vided into two parts. 



3. The Didimophydece, or Gregarince whose body is divided into 

 three portions, as if it resulted from the adhesion of two individuals, 

 one from each of the preceding families. 



The envelope of the Gregarince consists of a hyaline, transparent, 

 smooth and elastic membrane. Sometimes the outer surface is pro- 

 longed into immoveable filaments or into vibratile cilia (Henle found 

 the latter to be the case in the Gregarince from the Lumbrici). 

 The interior presents not a trace of organization ; it is filled with 

 a liquid, probably albuminous, in which a considerable number of 

 globules float, which the author considers to be globules of fat. The 

 young individuals contain a less number, and are consequently more 

 transparent. Dr. Stein confirms the presence of a nucleus placed 

 freely in the contents of the Gregarince. It is always simple in the 

 Monocystidece and the Gregarinariece; one species of the third 

 family exhibited two, another contained but one. Although the re- 

 production of these singular organisms is still quite obscure, several 

 facts appear to throw some light upon the subject. One of the most 

 important is the following observation of Von Siebold. 



The thin intestines of a dipterous larva (Sciara nitidicollis) con- 

 tain, along with numerous Gregarince (G. caudata), a large number 

 of round vesicles filled with innumerable minute bodies of a turnip 

 shape, called Navicellse by Von Siebold. They are composed of a 

 soft nucleus, and of a hard and transparent envelope. Henle again 



