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XXXIX. On a Gall gathered in Cuba by W . S. Macleay, Esq., upon the Leaf 

 of a Plant belonging to the Order Ochnaceœ. By the Rev. M. J. Berkeley, 

 M.J., F.L.S. 



Read April 16th, 1839. 



In following out any branch of natural history, the attentive student is con- 

 stantly struck with the host of unexpected analogies which meet him on every 

 side. He is not surprised to find a complicated network of relations, whether 

 of analogy or affinity, in his own particular department, but though his know- 

 ledge out of that is but superficial, he is astonished at observing how many 

 analogies present themselves, which at first, perhaps, he is inclined to think 

 fanciful or scarcely worth notice, but their number and importance increase 

 on him so fast, that at length he is forced to acknowledge the fact, that pecu- 

 liarities of form, structure, colouring, &c. are represented by similar peculiari- 

 ties in other apparently but little related orders. 



It is most curious, for instance, to find the diflferent organs of which the 

 more perfect plants are composed represented by various minute Algae and 

 Fungi, a circumstance, to which, perhaps, is owing the great success which 

 has attended the physiological researches of various close observers or students 

 of Cryptogamic plants, as Link, Mirbel, Mohi, Meyen, &c., and which has 

 caused Agurdh*, in perhaps rather too exclusive terms, to call the attention 

 of all inquirers into the more intimate structure of phaenogamous plants to his 

 own favourite department of sciencef. 



* Agardh, Organographie der Pflanzen, p. 101, note. 



t As an instance of this, the analogy between the helices of spiral vessels and the flocci or sporidia 

 of Helicomyces, Helicosporium and Helicotrichum, pointed out by Kunze in his Mycologische Hefte, may 

 be mentioned. It might be objected, that the articulations of the plants in question differ from any- 

 thing in spiral vessels ; but it is very curious that Meyen (Neues Syst. Pflanz. Phys. vol. i. tab. 4. fig. 8.) 

 has lately discovered articulated helices in the cells of Oiicidium maximum. Here an analogy recog- 

 nized between the fungi in question and the helices of spiral vessels might, if considered attentively, 

 have been an index of the probability of the existence of articulated helices in some phaenogamous 



