DR. MARTIN BARRY ON FIBRE. 107 



we cannot but be struck with the great uniformity in type in the earliest stages of 

 formation, however widely different the structures ultimately formed. 



78. On a late occasion-)-, I showed the foundation of the new being, in what are 

 called the highest animals, to have the same structure as that of the simplest plant. 

 We now find this uniformity in type to be recognizable at later periods. For, not 

 only does every tissue seem to arise out of discs having all the same appearance, but 

 the primary arrangement and early metamorphoses of these discs seem to be the 

 same. We recognize the same combination of spiral threads in the mould of cheese, 

 as in the brain of Man. How wonderful the fact, that out of materials so similar, 

 structures should be formed endowed with properties so different ! 



79. I have had an opportunity of examining the spermatozoon from the epididymis 

 of a person who died suddenly J. The large extremity appears to me to be a disc, the 

 pellucid depression in which, corresponding apparently to the '* sugient orifice" of 

 some authors, is probably analogous to the source of new substance in other discs. 

 Each of the two sides of the peripheral portion of the disc is extended into a thread : 

 these two threads forming, by being twisted, the part usually designated as the tail; 

 an appendage the office of which appears to be to " scull" along to its destination the 

 essential part or disc, and more particularly its pellucid centre. The formation of the 

 " tail," as now described, out of two twisted threads, seems to explain the observation 

 of R. WAGNER, who, in rare instances, met with the caudal part double (as I sup- 

 pose, untwisted) at the end. The caudal portion of the spermatozoon in the Rabbit 

 presented a similar structure. 



On the Structure and Mode of Increase of the Vegetable Spiral. On the Reticulated 

 Duct, Annular Duct, and Dotted Duct of Plants. 



80. Having added to spirals from the leaf-stalk of the strawberry, a spiritous solu- 

 tion of corrosive sublimate (par. 7), I soon discerned in their substance something 

 like a compound structure. In about half an hour, the interior of these spirals pre- 

 sented the appearance at a in fig. 71 : that is to say, they were seen to contain two 

 filaments, such as those above described. I therefore consider these spirals to be 

 reproduced in the same manner as those of muscle (figs. 68 to 70 and 73) and of 

 flax (fig. 113 , a ), which I find to become double and quadruple by self-division. 



81. It may be added, that, were the division of the spiral, or at least the separa- 

 tion, to be complete in some parts and not in others, the appearance would resemble 

 that of what is called the " reticulated duct." And the tendency (as it is supposed) 

 of vegetable "fibre" to anastomosis, might be thus explained. 



82. Rings have been mentioned (par. 34), as observed in animal structure ; which 

 rings divide, and pass into coils. Coils are met with (fig. 22 |3) that are equidistant, 



t Philosophical Transactions, 1839, p. 372. 



J For which I am indebted to the kindness of my friend ROBERT H. COOKE of Stoke Newington. 



P2 



