826 nAVENPQRT ACADEMY OF NATURAL SCIENCES*. 



a specific gravity less than watei* and not readily stained with eosene or 

 magenta, and which have an appearance similar to the yolk globules in 

 the egg. Probably fat or food globules. 



Third. Exceedingly minute, apparently spherical, bodies having a 

 specific gravity greater than water, and staining readily with eosene 

 (fig. 2). When stained a portion remains unstained as though there was- 

 3 vacuole. In water and some other mediums they exhibit an active 

 vibratory motion (brownian movement) which ceases after several hours.^ 

 They sometimes show a distinct but slow and uncertain progressive 

 movement. The nature and function of these bodies I do not under- 

 stand. They certainly bear a very strong resemblance to bacteria, and 

 may really be parasitic, or, it is po.fsible they may belong normally to 

 the insect, perhaps corresponding to the blood disks, and I have thought 

 of them in connection with the spermatozoa and fertilization of the eggs, 

 and also as being an early stage of the /ourf/i class of bodies next des- 

 cribed. Whatever they may be, they are always found in great abun- 

 dance in the females of this species at all times, and I have noticed 

 them in motion while still in the body cavity of the larva, I have fre 

 quently observed similar vibrating bodies in various diseased animal 

 matter, as tumors, etc. 



Fourth. Small oval bodies 3 // to 5 u in diameter, and about 10 // long, 

 having a specific gravity greater than water, (tig. 4). When highly mag- 

 nified they are seen to be composed of a greater or less quantity of fine 

 granular matter imbedded in a rather thick coating of some transparent 

 s^ubstance. Tliislast though easily stained brown by iodine remains unaf- 

 fected by eosene or magenta, except in a few in&tances where the external 

 envelope appears to be imperfect, in which case the granules become 

 stained leaving the envelope unstained. These bodies in general appear 

 to be very uniform in size and shape, usually regularly oval, often slightly 

 constricted in the middle. But a careful study made since the plate was 

 etched, shows a greater variation than I before supposed. Some are 

 seen to taper to a point at one end (fig. 4,c), others wliile preserving the 

 oval form have a small projection at one end, in others the projection is 

 a little larger, in others it is still larger and of an oval form, in others a 

 s-imilaroval body to the original and finally two, three or more full sized 

 bodies may be seen strung together end to^end. In some, as fig. 4,6, the 

 granules api>ear sepai'ated into two groups. A comparatively small 

 number of these bodies are already found in the females immediately 

 after copulation with the males, so they may have been present before 

 that event had taken place. They become exceedingly abundant during 

 the final development of the eggs in the spring, at which time they are 

 found in great numbers in all parts of the ovaries. At a certain period 

 in the development of the egg, just before it takes final leave of the egg 

 follicle, several of these bodies appear to enter at the head end, where 

 they become disintegrated, and soon after this, never before, the embryo 

 begins to form. On this account I for a long time believed them to be 

 spermatopbores, the contained granules being the spermatozoa, and that 

 they were derived from, the sperm filaments of the male by a process of 



