232 HETEROGENETIC ORIGIN 



A ( X soo), we have an aggregate of Bacteria, as an individualised 

 portion of a hay pellicle, slightly stained with chrysoidin, and 

 separating from it in the same kind of way that we have seen the 

 discrete corpuscles and Zoogloea masses individualising themselves 

 and separating from the pellicles in which they have been formed. 

 In B (x 500), we have an unstained specimen which is obviously 

 a mere spherical aggregate of Bacteria similar to those existing in 

 the peUicle around, and as yet without a definite bounding mem- 

 brane. A similar identity between the Bacterial contents of the 

 matrices, and those existing around them, will also be seen in each 

 of the other specimens represented in this and in Fig. 47. So that 

 in this important respect the embryo matrices agree exactly with 

 what we found to hold good for the small Zoogloea masses. A 

 matrix, stained with a very dilute eosinophile solution, which was 

 found in an infusion of Melica nutans^ is shown in Fig. 46, C ( X 375), 

 while in D ( X 375), we have two spherical aggregations of Bacteria, 

 the smaller of which is very distinctly developing a limiting enve- 

 lope. In E ( X 250), we have a small matrix found in a hay pellicle 

 with many others, and staining exactly like them with mastzellen 

 fluid. It is a mere aggregate of minute Bacteria though bounded 

 by a distinct limiting membrane. In F ( X 375), we have a larger 

 matrix, unstained, and from a different infusion. Here the bound- 

 ing membrane is very distinct, though there is, as yet, no sign of a 

 nucleus within the enclosed mass. 



This question, as to the early composition and development of the 

 matrices, being so very important, other illustrations are furnished 

 in Fig. 47. In A ( X 375), a nucleated matrix stained with mast- 

 zellen fluid is represented from a hay infusion. It is again a mere 

 aggregate of Bacteria having a distinct limiting membrane, though 

 here there is also a distinct nucleus. Two of these rudimentary 

 matrices, with cleai-ly-defined limiting membranes, but no trace of a 

 nucleus, from an infusion of Melica, are shown in B (x 375). The 

 dark masses in this, and in the next two figures, are groups of brown 

 Fungus-germs out of focus. C ( X 250) shows a group of matrices 

 in different stages of development from a hay infusion on the fifth 

 day. The specimen from which this photograph was taken had 

 been beneath a cover-glass for twenty-four hours previously, in a 

 very dilute solution of mastzellen stain. The pale vesicular bodies 

 are mature matrices which had, in the meantime, become much 

 altered by the formation of numerous vacuoles. Four other imma- 

 ture matrices, however, are well seen. The one above and to the 



