70 Contributions towards Establishing the General Character 

 I have endeavoured in the annexed sketch, to represent one of the 



forks or branches (a) of this specimen, with its appendages (h) penetrating 

 the laminse (c c.) The lateral appendages are not represented ; but it may 

 be stated, that they run out in the same plane as that of the branch — 

 thus agreeing with the diagram before mentioned. With respect to 

 the appendages which proceeded from the upper surface, it may, I 

 think, be safely concluded from the concurrent testimony of Steinhauer, 

 Hutton, Logan, and others, as to the direction of similarly situated 

 appendages found on other specimens of Stigmaria, when in situ, that 

 they passed upwards, and probably formed the same angle with the 

 branch as is made by their analogues on the under surface. 



Respecting the question as to how have the appendages become so 

 regularly arranged in their matrix, which, judging from the perfect 

 parallelism of its constituent laminee, shews that no obstruction pre- 

 vailed during its deposition, — there can, I think, be only one opinion, 

 which is, that the matrix was deposited in the first instance, and, that 

 the appendages penetrated the latter, when it was in a yielding condi- 

 tion. To bring forward arguments in support of this opinion is clearly 

 superfluous, since it is demonstrated by the simple fact of the laminse of 

 deposition being so regularly arranged. Had the matrix been deposited 

 upon or around the appendages, it is difficult to conceive any thing else 

 than that the laminse would have been exceedingly irregular. But, admitting 

 for a moment that Stigmaria was a floating plant, under what circum- 

 stances, I would ask, have the inferior appendages been able to preserve 

 a downward, the lateral ones a horizontal, and the superior ones an up- 

 right direction ? The only way to account for these facts, is to suppose 

 that the appendages were of the nature of spines, and strong enough 

 to have retained their original direction, had the plant become stranded 

 or covered up with silt ; but against such a supposition may be urged 

 the succulent nature of the appendages, as proved by their being com- 

 posed, with the exception of a central bundle of spiral vessels, of a thin 

 walled cellular tissue,* and by their occasionally being found twisted 

 and matted together in the greatest confusion. Thus, no circumstance 

 can be conceived to render, even probable, the opinion that Stigmaria was 

 a floating plant ; but, on the contrary, every thing evinces the sound- 



* Goeppart " Uber die Stigmaria eine neue Familie der VorweltUchen 

 Plora," in Karsten and Von Dechen's Archives, xiv., 1840, 



