Vegetable Mortars. 255 



Dr. Johnson intimates, where we have nothing to say, it is 

 better to say nothing.* 



A branched thread which forms the root penetrates the 

 matrix, the tip of which is elongated and swollen, and ulti- 

 mately is divided by a transverse partition from the mother 

 thread. The contents of this second joint circulate round the 

 walls, leaving a cavity in the centre. The apex is gradually 

 separated by a constriction from the lower part, and assumes a 

 globular form with a dark tint, while the top of what is now 

 the stem swells out like the hood of a cobra ; a second parti- 

 tion is formed between the two, which gradually protrudes, 

 pressing forcibly against the sporangium, and at the time when 

 the spores are matured, the pressure from behind becomes so 

 great, that the outer coat of the sporangium separates all 

 round at the dissepiment, and the sporangium itself is ejected 

 to a distance of several inches. Sometimes the partition 

 collapses at the moment of explosion, and sometimes it pro- 

 trudes permanently at the top, but it does not appear that a 

 second sporangium is formed, as is the case with some of the 

 Saprolegnice, as was observed in the Intellectual Observer, 

 April, 1864. The outer coat of the peridium is of a deep 

 black, and appears minutely granulated under a high power, 

 and adheres readily to any object on which it may chance to 

 impinge. The inner contains a compact mass of minute sub- 

 globose spores. These spores do not germinate very readily; 

 but it is probable that, like those of the mushroom, and some 

 allied Agarics, they require to pass through the stomach of 

 some graminivorous or omnivorous animal to facilitate their 

 germination. The vegetation of the plant is extremely rapid, 

 the whole process being accomplished in about two days : the 

 vegetative part, at least, is developed and disappears in the 

 course of twenty-four hours. The affinities of the plant are 

 very different from those of the Sphcerobolus , and undoubtedly 

 are with the true moulds (Mucorini, not Mucedines). 



One or two species are assigned to either genus, but I have 

 thought it necessary to refer only to the more common kind of 

 each. 



Fries has another genus, Atractobolus ,f taken up from 

 Tode, but it is very doubtful whether it be a fungus at all. 

 What is commonly supposed to be the production is simply 

 the egg of some mite of the genus Rhipignathus, the contents 

 being taken for a sporangium. Thelebolus, which is placed 



* The exact phrase occurs in a letter to Boswell, dated July 3, 1778, " You 

 must not think me criminal or cold, if I say nothing when I have nothing to say ;" 

 which is to the same effect as the advice commonly said to have heen given by 

 Lord Brougham to Lord Campbell. 



-ilTrciE&TpaKTos, a spindle, and /3aAA«, I cast. 



