1) In a former paper (4), the segregations of spiny versus spineless fruits was described as caused by one pair of mendelian factors, but in view of the possible pratical importance of spineless fruits a more detailed study was thought desirable. We may distinguish three main types of the distribuition of spine among the different varieties in our collections: Spineles fruits (inerms), found in a number of varieties. "Bald" fruits (a type called "careca" or bald owing to the irregular distribuition of the spines, which were always absent in some parts of the fruits while otrer patches might contain spines. Spiny fruits which may be classified into two or more groups, according to the number of regularly distributed spines. 2) The cross (spineless fruits) x (fruits with regularly distributed spines) HARLAND (7), PEAT (9) e FERNANDES (3) observed a 1:2:1 segregations in F2 while GURGEL (4) and DOMINGO (2) find it difficult to distinguish the homozygous and heterozygous spiny types without counting the number of spines. Such counts and the results of a detailed statistical analysis are now given. They show that the results of the 1:2:1 segregations are somewhat modified by both phenotypic modifications of the number of spines. The latter are caused by modifier genes introduced by both parents. 3) The cross between plants with a regular and an irregular distribuition of spines showed that the latter condition is due to the presence of two recessive complementary factors. Thus we have in F2, 15 regular to 1 irregular or partially "bald", and in back-crosses segregations in acordance with the ratio 3:1. 4) The cross spineless x "Careca", gave, as might be expected a trifatorial segregation in accordance with the following formula. "Inermes" "Careca" P : ss CalCal Ca2Ca2 x SS ca1ca1 ca2ca2 Fl : Ss CalCal Ca2Ca2 (with regularly distributed spines) F2 : 45 S- Cal- Ca2- (spines regularly distributed). 3 S- calca1 ca2ca2 ,"Careca) 16 ss ("inermes").