MM. Tulasne on the History of the Hypogceous Fungi. 19 



Fig. 8. is the larva of Sipunculus after Max. Miiller. 



Fig. 9. The larva of an Anuelid after Milne-Edwards. 



Fig. 10. Aiiricularia. The larva of Holothuria, after Miiller; to show the 



mode of development of the water-vascular system, &c. from the 



internal bud, d : e, the oval masses of cells. 

 Fig. 1 1 . One of the epauletted Echinus-larvae, in which the Echinoderm, d, 



has already begun to envelope the stomach of the larva. 



IX. X. XI. XII. XIII. are diagrams intended to represent the mode of 

 development of an Asterias within its larva the Bipinnaria. 

 The form of the latter is not given ; its relation being indicated only by 

 the dotted line. 



IX. m, the mouth of the larva ; a, its anus ; d, the bud-like commencement 



of the Echinoderm. 



X. XI. The latter has developed the water-canals, and with its accom- 



paming blastema has begun to invest the stomach of the larva. 



XII. The investment nearly complete. The position of the mouth of the 



Asterias indicated by (o). 



XIII. The Echinoderm has become free and separate from the body of the 



larva with its primitive oesophagus. 



It is to be understood that these diagrams do not pretend to be strictly 

 accurate. They are intended only to render the process of development 

 more easily comprehensible. 



II. — Report on MM. L. R. and C. Tulasne^s " Memoir on the 

 History of the Hypogaous Fungi." By MM. Jussieu and 

 Ad. Brongniart*. 



The mode of vegetation and reproduction of the Fungi had long 

 been one of the most obscure portions of the vegetable kingdom, 

 and, in spite of the progress of this department of botany during 

 the last fifty years, many points yet remain to be cleared up ; but 

 in this vast class, the anomalous organization of which has caused 

 some naturalists to regard them as a kind of peculiar kingdom, 

 nothing perhaps is more singular than the development of the 

 subterranean Fungi, the whole life of which, the growth and re- 

 production, goes on in the bosom of the earth, without any por- 

 tion of their structure coming to the surface. 



This existence, entirely removed from the action of light, is an 

 anomaly even among the plants of the Fungous class, which, ge- 

 nerally speaking, prefer weakly illuminated situations ; for ordi- 

 nary Fungi cannot live in complete obscurity without becoming 

 profoundly altered in form and structure, and being kept im- 

 perfect and sterile. Light therefore, although in less degree 

 necessary to Fungi than to ordinary vegetables, is almost always 

 indispensable to their regular development at least at the period 

 of reproduction. 



For a long period the common Truffle, and a few other equally 



* Comptes Rendus, Dec. 30, 1850. 



2* 



